test: Disable automatic connections by default

This prevents the node from trying to connect to random IPs on the internet
while running the functional tests. Exceptions are added when required for
the test to pass.

test/functional/feature_config_args.py

@@ -17,6 +17,7 @@ class ConfArgsTest(BitcoinTestFramework):
         self.num_nodes = 1
         self.supports_cli = False
         self.wallet_names = []
+        self.disable_autoconnect = False
 
     def test_config_file_parser(self):
         self.stop_node(0)