Description of problem:
Using HttpRouter to connect to https:// requires to specify information about the ssl key. If the keystore location is not explicitly defined, '/keystore' is used as default location.

This default location should be changed to use the default JRE keystore location - ${JAVA_HOME}/lib/security/cacerts


Version-Release number of selected component (if applicable):
JBossESB 4.10

How reproducible:
Always

Steps to Reproduce:
1. Set up HttpRouter with https:// target endpoint
2. Don't explicitly  set the "keystore" property
  
Actual results:
Initialization fails:

Caused by: org.jboss.soa.esb.ConfigurationException: Failed to locate keystore '/keystore'.
        at org.jboss.soa.esb.http.configurators.HttpProtocol.getKeyMaterial(HttpProtocol.java:200)
        at org.jboss.soa.esb.http.configurators.HttpProtocol.configure(HttpProtocol.java:94)
        at org.jboss.soa.esb.http.HttpClientFactory.createHttpClient(HttpClientFactory.java:84)
        at org.jboss.soa.esb.actions.routing.http.HttpRouter.<init>(HttpRouter.java:113)


Expected results:
Initialization succeeds by using the default keystore location. An INFO message could inform the user that the default keystore is used.