Request body: adjust b->pos when chunked parsing done.

This is a nop for the current code, though will allow to correctly parse
pipelined requests.

src/http/ngx_http_parse.c

diff --git a/src/http/ngx_http_parse.c b/src/http/ngx_http_parse.c
index cbc412c..a6ee74e 100644
--- a/src/http/ngx_http_parse.c
+++ b/src/http/ngx_http_parse.c
@@ -2065,6 +2065,9 @@
 
 done:
 
+    ctx->state = 0;
+    b->pos = pos + 1;
+
     return NGX_DONE;
 
 invalid: