Description of problem: 
The build process does a git ls-remote to check if a repo is accessible. the timeout is hardcoded at 16s. Since, it is not able to get repository it timesout after 16 seconds.


Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1. oc start-build aaabbb --follow --build-loglevel=5
aaabbb-3
I0516 16:50:24.256697       1 builder.go:41] $BUILD env var is {"kind":"Build","apiVersion":"v1","metadata":{"name":"aaabbb-3","namespace":"mat","selfLink":"/oapi/v1/namespaces/mat/builds/aaabbb-3","uid":"ce5ff12c-1ba7-11e6-8a43-0a5d3910846d","resourceVersion":"80148","creationTimestamp":"2016-05-16T20:50:21Z","labels":{"app":"aaabbb","buildconfig":"aaabbb","openshift.io/build-config.name":"aaabbb"},"annotations":{"openshift.io/build.number":"3"}},"spec":{"serviceAccount":"builder","source":{"type":"Git","git":{"uri":"https://github.com/openshift/nodejs-ex.git","ref":"master"}},"strategy":{"type":"Source","sourceStrategy":{"from":{"kind":"DockerImage","name":"registry.access.redhat.com/openshift3/nodejs-010-rhel7:latest"},"env":[{"name":"BUILD_LOGLEVEL","value":"5"}]}},"output":{"to":{"kind":"DockerImage","name":"172.30.3.99:5000/mat/aaabbb:latest"},"pushSecret":{"name":"builder-dockercfg-zlcji"}},"resources":{}},"status":{"phase":"New","outputDockerImageReference":"172.30.3.99:5000/mat/aaabbb:latest","config":{"kind":"BuildConfig","namespace":"mat","name":"aaabbb"}}}

I0516 16:50:24.263935       1 sti.go:167] With force pull false, setting policies to if-not-present
I0516 16:50:24.263951       1 sti.go:173] The value of ALLOWED_UIDS is [1-]
I0516 16:50:24.263966       1 cfg.go:45] Locating docker auth for image registry.access.redhat.com/openshift3/nodejs-010-rhel7:latest and type PULL_DOCKERCFG_PATH
I0516 16:50:24.264019       1 cfg.go:81] Using Docker authentication configuration in '/root/.docker/config.json'
I0516 16:50:24.264327       1 cfg.go:53] Problem accessing /root/.docker/config.json: stat /root/.docker/config.json: no such file or directory
I0516 16:50:24.264340       1 cfg.go:45] Locating docker auth for image 172.30.3.99:5000/mat/aaabbb:latest and type PUSH_DOCKERCFG_PATH
I0516 16:50:24.264344       1 cfg.go:81] Using Docker authentication configuration in '/var/run/secrets/openshift.io/push/.dockercfg'
I0516 16:50:24.264497       1 cfg.go:67] Using serviceaccount user for Docker authentication for image 172.30.3.99:5000/mat/aaabbb:latest
I0516 16:50:24.275448       1 docker.go:224] Image registry.access.redhat.com/openshift3/nodejs-010-rhel7:latest available locally
I0516 16:50:24.277739       1 sti.go:195] Creating a new S2I builder with build config: "Builder Name:\t\tNode.js 0.10\nBuilder Image:\t\tregistry.access.redhat.com/openshift3/nodejs-010-rhel7:latest\nSource:\t\t\tfile:///tmp/s2i-build739792746/upload/src#master\nOutput Image Tag:\t172.30.3.99:5000/mat/aaabbb:latest\nEnvironment:\t\tOPENSHIFT_BUILD_NAME=aaabbb-3,OPENSHIFT_BUILD_NAMESPACE=mat,OPENSHIFT_BUILD_SOURCE=https://github.com/openshift/nodejs-ex.git,OPENSHIFT_BUILD_REFERENCE=master,BUILD_LOGLEVEL=5\nIncremental Build:\tdisabled\nRemove Old Build:\tdisabled\nBuilder Pull Policy:\tif-not-present\nQuiet:\t\t\tdisabled\nLayered Build:\t\tdisabled\nWorkdir:\t\t/tmp/s2i-build739792746\nDocker NetworkMode:\tcontainer:c3e047b3a27e3e95cb2de024a49eb3fde7fd0395c7f208180af9e2db3a6ecd27\nDocker Endpoint:\tunix:///var/run/docker.sock\n"
I0516 16:50:24.280294       1 docker.go:224] Image registry.access.redhat.com/openshift3/nodejs-010-rhel7:latest available locally
I0516 16:50:24.284749       1 sti.go:201] Starting S2I build from mat/aaabbb-3 BuildConfig ...
I0516 16:50:24.284764       1 sti.go:140] Preparing to build 172.30.3.99:5000/mat/aaabbb:latest
I0516 16:50:24.287061       1 source.go:96] git ls-remote https://github.com/openshift/nodejs-ex.git --heads
I0516 16:50:24.287103       1 repository.go:275] Executing git ls-remote https://github.com/openshift/nodejs-ex.git --heads
I0516 16:50:40.288169       1 cleanup.go:23] Removing temporary directory /tmp/s2i-build739792746
I0516 16:50:40.288190       1 fs.go:117] Removing directory '/tmp/s2i-build739792746'
F0516 16:50:40.288428       1 builder.go:185] Error: build error: timeout while waiting for remote repository "https://github.com/openshift/nodejs-ex.git"
2.
3.

Actual results: Fails everytime after 16 seconds with no clear message


Expected results: 

1) the timeout should be configurable
2) And a clearer message should be displayed


Additional info: https://github.com/openshift/origin/issues/8772