isMemberOfGroups fix
closes #1883, no upgrade script #successkid
check for valid content, #1884
Merge branch 'master' of github.com:NodeBB/NodeBB

* 'master' of github.com:NodeBB/NodeBB:
  check for valid content, #1884
  closes #1883, no upgrade script #successkid
  isMemberOfGroups fix