[PLG_AUTHENTICATION_GOOGLE] fix for potentially undefined var
[PLG_AUTHENTICATION_GOOGLE] fix for potentially undefined var

anthonyfuentes/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,zooley/hubzero-cms