fix(core): avoid pooling channels with tools (fixes #4684)

Tools/SOGoToolCheckupUser.m

@@ -1,6 +1,6 @@
 /* SOGoToolCheckup.m - this file is part of SOGo
  *
- * Copyright (C) 2017 Inverse inc.
+ * Copyright (C) 2017-2020 Inverse inc.
  *
  * This file is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -128,7 +128,7 @@
               if (user)
                 [allSqlUsers addObject: user];
             }
-          [cm releaseChannel: fc];
+          [cm releaseChannel: fc  immediately: YES];
 
           users = allSqlUsers;
           max = [users count];