qa: Fix double-negative arg test

Author: hebasto

test/functional/feature_config_args.py

@@ -79,7 +79,7 @@ def test_config_file_parser(self):
             conf.write('')  # clear
 
     def test_log_buffer(self):
-        with self.nodes[0].assert_debug_log(expected_msgs=['Warning: parsed potentially confusing double-negative -connect=0']):
+        with self.nodes[0].assert_debug_log(expected_msgs=['Warning: parsed potentially confusing double-negative -connect=0\n']):
             self.start_node(0, extra_args=['-noconnect=0'])
         self.stop_node(0)