Merge bitcoin/bitcoin#21814: test: Fix feature_config_args.py intermittent issue

fab1eb6 test: Fix feature_config_args.py intermittent issue (MarcoFalke)

Pull request description:

  Fix #21448

ACKs for top commit:
  laanwj:
    Code review ACK fab1eb6

Tree-SHA512: cad9f684f43aa801d0c1cb5f1684ffa624df1216be225cea46b1389ba2b67cbd6159ffb786fe144bf1ca865623dd9a10289d4293cfabb678bdb243d4ea00734d

Author: MarcoFalke

test/functional/feature_config_args.py

@@ -165,6 +165,7 @@ def test_seed_peers(self):
         with self.nodes[0].assert_debug_log(expected_msgs=[
                 "Loaded 0 addresses from peers.dat",
                 "0 addresses found from DNS seeds",
+                "opencon thread start",  # Ensure ThreadOpenConnections::start time is properly set
         ]):
             self.start_node(0, extra_args=['-dnsseed=1', '-fixedseeds=1', f'-mocktime={start}'])
         with self.nodes[0].assert_debug_log(expected_msgs=[
@@ -206,6 +207,7 @@ def test_seed_peers(self):
         with self.nodes[0].assert_debug_log(expected_msgs=[
                 "Loaded 0 addresses from peers.dat",
                 "DNS seeding disabled",
+                "opencon thread start",  # Ensure ThreadOpenConnections::start time is properly set
         ]):
             self.start_node(0, extra_args=['-dnsseed=0', '-fixedseeds=1', '-addnode=fakenodeaddr', f'-mocktime={start}'])
         with self.nodes[0].assert_debug_log(expected_msgs=[