Merge pull request #2508 from xillibit/k30_bugs4

AUP: Not possible to get points and medals
Migration from tables "prefix_fb" does not works with Kunena 3.0 #2211
Merge pull request #2516 from xillibit/k30_bugs12

Migration from tables "prefix_fb" does not works with Kunena 3.0 #2211
K3.1: blue eagle : Cannot hide admins in userlist #793 (backport fix)