[9.20] fix: dev: Don't ignore the local port number in dns_dispatch_add() for TCP
The dns_dispatch_add() function registers the 'resp' entry in 'disp->mgr->qids' hash table with 'resp->port' being 0, but in tcp_recv_success(), when looking up an entry in the hash table after a successfully received data the port is used, so if the local port was set (i.e. it was not 0) it fails to find the entry and results in an unexpected error.
Set the 'resp->port' to the given local port value extracted from 'disp->local'.
Closes #4969 (closed)
Backport of MR !9576 (merged)