auto_socket.c: remove tsrv from inst->stcp_servers before stcp_link_server_destroy
when TCP socket has null addr — freed pointer stayed in linked list corrupting it
on next stcp_server_listen->stcp_server_list_add, causing hang
utun_instance.c: apply debug_level + per-category debug from config in
utun_instance_create_from_config (was only in utun_instance_create)
chat_core.c: verbose error log on invalid args
evgeny
de61a2dacc