[scripts][execute] Cleanup db_addr handling

beat/backend/python/scripts/execute.py

@@ -180,10 +180,11 @@ def main():
 
     # Creates the 0MQ socket for communication with the databases (if necessary)
     db_socket = None
-    if args["<db_addr>"]:
+    db_addr = args.get("<db_addr>")
+    if db_addr:
         db_socket = context.socket(zmq.PAIR)
-        db_socket.connect(args["<db_addr>"])
-        logger.debug("zmq client connected to db `%s'", args["<db_addr>"])
+        db_socket.connect(db_addr)
+        logger.debug("zmq client connected to db `%s'", db_addr)
 
     loop_socket = None
     loop_addr = args.get("--loop")