Merge bitcoin/bitcoin#30512: net: Log accepted connection after m_nodes.push_back; Fix intermittent test issue

fa3ea3b test: Fix intermittent issue in p2p_v2_misbehaving.py (MarcoFalke)
5555557 net: Log accepted connection after m_nodes.push_back (MarcoFalke)

Pull request description:

  Fix the two issues reported in https://github.com/bitcoin/bitcoin/pull/30468/files#r1688444784:

  * Delay a debug log line for consistency.
  * Fix an intermittent test issue.

  They are completely separate fixes, but both `net` related.

ACKs for top commit:
  0xB10C:
    Code Review ACK fa3ea3b
  stratospher:
    tested ACK fa3ea3b.

Tree-SHA512: cd6b6e164b317058a305a5c3e38c56c9a814a7469039e1143f1d7addfbc91b0a28506873356b373d97448b46cb6fbe94a1309df82e34c855540b241a09489e8b

Author: fanquake

src/net.cpp

@@ -1810,13 +1810,11 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                              });
     pnode->AddRef();
     m_msgproc->InitializeNode(*pnode, nLocalServices);
-
-    LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToStringAddrPort());
-
     {
         LOCK(m_nodes_mutex);
         m_nodes.push_back(pnode);
     }
+    LogDebug(BCLog::NET, "connection from %s accepted\n", addr.ToStringAddrPort());
 
     // We received a new connection, harvest entropy from the time (and our peer count)
     RandAddEvent((uint32_t)id);

test/functional/p2p_v2_misbehaving.py

@@ -140,7 +140,8 @@ def test_earlykeyresponse(self):
         node0.setmocktime(int(time.time()))
         self.log.info('Sending first 4 bytes of ellswift which match network magic')
         self.log.info('If a response is received, assertion failure would happen in our custom data_received() function')
-        peer1 = node0.add_p2p_connection(MisbehavingV2Peer(TestType.EARLY_KEY_RESPONSE), wait_for_verack=False, send_version=False, supports_v2_p2p=True, wait_for_v2_handshake=False)
+        with node0.wait_for_new_peer():
+            peer1 = node0.add_p2p_connection(MisbehavingV2Peer(TestType.EARLY_KEY_RESPONSE), wait_for_verack=False, send_version=False, supports_v2_p2p=True, wait_for_v2_handshake=False)
         peer1.send_raw_message(MAGIC_BYTES['regtest'])
         self.log.info('Sending remaining ellswift and garbage which are different from V1_PREFIX. Since a response is')
         self.log.info('expected now, our custom data_received() function wouldn\'t result in assertion failure')