Fixed up error handling

webgui/ajax.php

webgui/include/ajax/functions/AdminClientAttributes.php

webgui/include/ajax/functions/AdminClientRealms.php

webgui/include/ajax/functions/AdminClients.php

webgui/include/ajax/functions/AdminGroupAttributes.php

webgui/include/ajax/functions/AdminGroupMembers.php

webgui/include/ajax/functions/AdminGroups.php

webgui/include/ajax/functions/AdminRealmAttributes.php

webgui/include/ajax/functions/AdminRealmMembers.php

webgui/include/ajax/functions/AdminRealms.php

webgui/include/ajax/functions/AdminUserAttributes.php

webgui/include/ajax/functions/AdminUserGroups.php

webgui/include/ajax/functions/AdminUserTopups.php

webgui/include/ajax/functions/AdminUsers.php

webgui/include/ajax/functions/WiSPLocationMembers.php

webgui/include/ajax/functions/WiSPLocations.php

webgui/include/ajax/functions/WiSPUserTopups.php

webgui/include/ajax/functions/WiSPUsers.php

webgui/include/ajax/json.php