Fix Bug where confbridge.py would not start if there was not an ACL defined.

confbridge.py

@@ -150,14 +150,13 @@ def make_bridge_config(_confbridge_rules):
 # Global action is to allow or deny them. Multiple lists with different actions and ranges
 # are not yet implemented.
 def build_acl(_sub_acl):
+    ACL = set()
     try:
         logger.info('ACL file found, importing entries. This will take about 1.5 seconds per 1 million IDs')
         acl_file = import_module(_sub_acl)
         sections = acl_file.ACL.split(':')
         ACL_ACTION = sections[0]
         entries_str = sections[1]
-        ACL = set()
-        
         for entry in entries_str.split(','):
             if '-' in entry:
                 start,end = entry.split('-')