#410 add_edit_event ancient bug

[Art Eaton]

 if ($userid) {
            if ( in_array($urow['id'], $providers_array) || ($urow['id'] == $userid) ) echo " selected";
        }

    Gets you about a million of the following in your php error log:
    in_array() expects parameter 2 to be array, null given in C:\xampp\htdocs\openemr\interface\main\calendar\add_edit_event.php on line 1311

    Before 4.2, this used to be on line 1280.  Back in version 2.8.3 it was on line 988.  This has been around for a while.