Description of problem:
When file 'app.py' exists, the stop action can't kill the 'python app.py' process after start it twice.

Version-Release number of selected component (if applicable):
puddle [2.1.z/2014-08-13.1]

How reproducible:
100%

Steps to Reproduce:
1. Create a pyhon app
#rhc app create ajeamkpi python-3.3 mongodb-2.4 --from-code https://github.com/openshift-quickstart/Bottle-Python3-quickstart 
2.Start the app twice
#rhc app start ajeamkpi
3. Stop the app
#rhc app stop ajeamkpi
4.access the app

Actual results:
The app is still accessible 

Expected results:
Can not access the app

Additional info:
vim python/usr/versions/3.3/bin/control 
function start_app()
...
    rm -f $LOGPIPE && mkfifo $LOGPIPE
    /usr/bin/logshifter -tag python < $LOGPIPE &
    nohup python -u app.py &> $LOGPIPE &
    if [ "$?" == "0" ]; then
      echo $! > $OPENSHIFT_PYTHON_DIR/run/appserver.pid
    else
These code only change the pid in $OPENSHIFT_PYTHON_DIR/run/appserver.pid when start the app for the second time