The STS endpoint is not used properly from connection string

[gcheng]

Dev:1
Test: 1

WrapRestProxyIntegrationTest unit fail
.com.microsoft.windowsazure.services.core.ServiceException: WRAP server returned error acquiring access_token

We do not add WRAP to the end of STS end point.

[gcheng]

start working on it!

[gcheng]

the fix should be in public repo because there is no interface change.

[xuezhai]

serverbus integration UT now is passing, sts endpoint should be handled correctly