Raise NetworkError when ScriptRunner fails to connect.
Raise NetworkError when ScriptRunner fails to connect.

Change-Id: I1d36685aa9b9035a8812908a60ad59a4d33de366
Fixes: rhbz#908838

bcrochet/packstack,xbezdick/packstack,weshayutin/packstack,radez/packstack,alincalinciuc/packstack,pkilambi/packstack,spkane/packstack,fr34k8/packstack,paramite/packstack,pkilambi/packstack,xbezdick/packstack,alincalinciuc/packstack,fr34k8/packstack,stackforge/packstack,derekhiggins/packstack,openstack/packstack,imcsk8/packstack,spkane/packstack,derekhiggins/packstack,radez/packstack,bcrochet/packstack,paramite/packstack,stackforge/packstack,bcrochet/packstack,stackforge/packstack,harveyzh/packstack,larsks/packstack,spkane/packstack,palmer159/openstack-test,mahak/packstack,weshayutin/packstack,larsks/packstack,imcsk8/packstack,mahak/packstack,harveyzh/packstack,paramite/packstack,openstack/packstack,imcsk8/packstack,radez/packstack,pkilambi/packstack,harveyzh/packstack,fr34k8/packstack,weshayutin/packstack,larsks/packstack,xbezdick/packstack,alincalinciuc/packstack,derekhiggins/packstack,palmer159/openstack-test,palmer159/openstack-test,openstack/packstack,mahak/packstack