Valgrind caught http/1.1 pipelining using dead user agent alloc
for logging... NULL it when we free it since the wsi can be
reused with keepalive
==16208== Invalid free() / delete / delete[] / realloc()
==16208== at 0x4847ACC: free (vg_replace_malloc.c:530)
==16208== by 0x4888DC3: _realloc (alloc.c:8)
==16208== by 0x4888DFF: lws_realloc (alloc.c:16)
==16208== by 0x487DBCB: lws_access_log (libwebsockets.c:2352)
==16208== by 0x48956DF: lws_http_transaction_completed (server.c:1245)
==16208== by 0x4893757: lws_http_serve (server.c:340)
==16208== by 0x48946EF: lws_http_action (server.c:748)
==16208== by 0x4894CEF: lws_handshake_server (server.c:900)
==16208== by 0x48786BF: lws_read (handshake.c:120)
==16208== by 0x4896103: lws_server_socket_service (server.c:1580)
==16208== by 0x487FB6B: lws_service_fd_tsi (service.c:779)
==16208== by 0x48803B7: lws_service_fd (service.c:1079)
==16208== Address 0x552e5f8 is 0 bytes inside a block of size 86 free'd
==16208== at 0x4847ACC: free (vg_replace_malloc.c:530)
==16208== by 0x4888DC3: _realloc (alloc.c:8)
==16208== by 0x4888DFF: lws_realloc (alloc.c:16)
==16208== by 0x487DBCB: lws_access_log (libwebsockets.c:2352)
==16208== by 0x48956DF: lws_http_transaction_completed (server.c:1245)
==16208== by 0x4893757: lws_http_serve (server.c:340)
==16208== by 0x48946EF: lws_http_action (server.c:748)
==16208== by 0x4894CEF: lws_handshake_server (server.c:900)
==16208== by 0x48786BF: lws_read (handshake.c:120)
==16208== by 0x4896103: lws_server_socket_service (server.c:1580)
==16208== by 0x487FB6B: lws_service_fd_tsi (service.c:779)
==16208== by 0x48803B7: lws_service_fd (service.c:1079)
==16208== Block was alloc'd at
==16208== at 0x4846498: malloc (vg_replace_malloc.c:298)
==16208== by 0x4848D57: realloc (vg_replace_malloc.c:785)
==16208== by 0x4888DA7: _realloc (alloc.c:6)
==16208== by 0x4888DFF: lws_realloc (alloc.c:16)
==16208== by 0x4893EAF: lws_http_action (server.c:565)
==16208== by 0x4894CEF: lws_handshake_server (server.c:900)
==16208== by 0x48786BF: lws_read (handshake.c:120)
==16208== by 0x4896103: lws_server_socket_service (server.c:1580)
==16208== by 0x487FB6B: lws_service_fd_tsi (service.c:779)
==16208== by 0x48803B7: lws_service_fd (service.c:1079)
==16208== by 0x48994B7: lws_io_cb (libuv.c:101)
==16208== by 0x4AE7B1F: ??? (in /usr/lib/libuv.so.1.0.0)
Signed-off-by: Andy Green <andy@warmcat.com>
54b856fea4