In groups widget AJAX handler, use array format to pass params to bp_has_groups()

See #2368

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8079 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Specify a null user when querying for groups in groups widget AJAX callback

This ensures that groups are not filtered according to the displayed user when
the widget appears on a user's profile page.

Fixes #2368

Props burakali

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8080 cdf35c40-ae34-48e0-9cc9-0c9da1808c22