net: avoid unnecessary GetBindAddress() call

Summary:
Our local (bind) address is already saved in `CNode::addrBind` and there
is no need to re-retrieve it again with `GetBindAddress()`.

Also, for I2P connections `CNode::addrBind` would contain our I2P
address, but `GetBindAddress()` would return something like
`127.0.0.1:RANDOM_PORT`.

This is a backport of [[bitcoin/bitcoin#20685 | core#20685]] [7/20]
bitcoin/bitcoin@f6c267d

Depends on D11015

Test Plan: `ninja all check-all`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11016

src/net.cpp

@@ -3152,9 +3152,7 @@ std::vector<CAddress> CConnman::GetAddresses(size_t max_addresses,
 
 std::vector<CAddress>
 CConnman::GetAddresses(CNode &requestor, size_t max_addresses, size_t max_pct) {
-    SOCKET socket;
-    WITH_LOCK(requestor.cs_hSocket, socket = requestor.hSocket);
-    auto local_socket_bytes = GetBindAddress(socket).GetAddrBytes();
+    auto local_socket_bytes = requestor.addrBind.GetAddrBytes();
     uint64_t cache_id =
         GetDeterministicRandomizer(RANDOMIZER_ID_ADDRCACHE)
             .Write(requestor.addr.GetNetwork())