HTTP/2: improved body reading logging.

src/http/v2/ngx_http_v2.c

diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c
index 3bef002..ac10c2a 100644
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -4154,6 +4154,9 @@
     rb = r->request_body;
     buf = rb->buf;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, fc->log, 0,
+                   "http2 process request body");
+
     if (size) {
         if (buf->sync) {
             buf->pos = buf->start = pos;
@@ -4364,6 +4367,9 @@
     stream = r->stream;
     fc = r->connection;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, fc->log, 0,
+                   "http2 read unbuffered request body");
+
     if (fc->read->timedout) {
         if (stream->recv_window) {
             stream->skip_data = 1;