allow comma/space delimiter for allowed_methods

Example config says, that comma is allowed, but it was not true.

Fixes: https://pagure.io/koji/issue/1744

plugins/hub/save_failed_tree.py

@@ -29,7 +29,7 @@ def saveFailedTree(buildrootID, full=False, **opts):
     # read configuration only once
     if config is None:
         config = koji.read_config_files([(CONFIG_FILE, True)])
-        allowed_methods = config.get('permissions', 'allowed_methods').split()
+        allowed_methods = config.get('permissions', 'allowed_methods').split(',')
         if len(allowed_methods) == 1 and allowed_methods[0] == '*':
             allowed_methods = '*'