Fix logic error in caching in BP_Groups_Group::populate()

Introduced in r7956, this bug cause the populate logic not to be run when
the cache was hit successfully. Mega-anti-props boonebgorges.

See #5407

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7974 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
xProfile: fix phpDoc for `xprofile_clear_profiledata_object_cache()`

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7975 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Inline doc, code formatting, and micro-optimizations to `BP_Groups_Group::populate()`.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7976 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
POT, generated from r7976

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7977 cdf35c40-ae34-48e0-9cc9-0c9da1808c22