HTTP/2: always send GOAWAY while worker is shutting down.

Previously, if the worker process exited, GOAWAY was sent to connections in
idle state, but connections with active streams were closed without GOAWAY.

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 19e5f3a..7e4736b 100644
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -615,7 +615,7 @@
     }
 
     if (ngx_terminate || ngx_exiting) {
-        ngx_http_close_connection(c);
+        ngx_http_v2_finalize_connection(h2c, NGX_HTTP_V2_NO_ERROR);
         return;
     }