fix request counter for post_action, the bug was introduced in r3050

src/http/ngx_http_request.c

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 25b2aff..07afe67 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2820,6 +2820,8 @@
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "post action: \"%V\"", &clcf->post_action);
 
+    r->main->count--;
+
     r->http_version = NGX_HTTP_VERSION_9;
     r->header_only = 1;
     r->post_action = 1;