Errors when adding new institution members (bug 1046114)

Once the members have been added and the change has been commited
to the database, logout each user who has been added.

Change-Id: I732c7fcbb5ea5913c5e3def8a7a3950c5e83e554
Signed-off-by: Nitish Bezzala <nbezzala@yahoo.com>

htdocs/lib/institution.php

@@ -277,6 +277,10 @@ class Institution {
             $this->addUserAsMember($user);
         }
         db_commit();
+
+        foreach ($users as $user) {
+            remove_user_sessions($user->id);
+        }
     }
 
     public function addRequestFromUser($user, $studentid = null) {