Added better checks for SQL failing

webui/group-add.php

webui/group-attribute-change.php

webui/group-delete.php

webui/group-main.php

webui/user-attribute-delete.php

webui/user-groups-delete.php

webui/wisp-multiuser-add.php

webui/wisp-user-delete.php

webui/wisp-user-edit.php