Fix issue with Modoboa driver for password plugin (#7372)

Was having trouble with updating a password with the Modoboa API (1.9.1). API responded with an error message but 200 HTTP status code, so roundcube displayed a success message even though the password wasn't being updated. Added a line to include a required field in the update request.

plugins/password/drivers/modoboa.php

@@ -82,6 +82,7 @@ class rcube_modoboa_password
 
         // Encode json with new password
         $ret['username'] = $decoded[0]->username;
+        $ret['mailbox'] = $decoded[0]->mailbox;
         $ret['role']     = $decoded[0]->role;
         $ret['password'] = $passwd; // new password
         $encoded         = json_encode($ret);