don't hint the GC for V2 mcp.internal

proxy_internal.c

@@ -1729,11 +1729,6 @@ static inline int _mcplib_internal_run(LIBEVENT_THREAD *t, mcp_request_t *rq, mc
     // Always return OK from here as this is signalling an internal error.
     r->status = MCMC_OK;
 
-    // resp object is associated with the
-    // response object, which is about a
-    // kilobyte.
-    t->proxy_vm_extra_kb++;
-
     return 0;
 }
 
@@ -1779,6 +1774,11 @@ int mcplib_internal_run(mcp_rcontext_t *rctx) {
 
     _mcplib_internal_run(t, rq, r, resp);
 
+    // resp object is associated with the
+    // response object, which is about a
+    // kilobyte.
+    t->proxy_vm_extra_kb++;
+
     if (resp->io_pending) {
         // TODO (v2): here we move the IO from the temporary resp to the top
         // resp, but this feels kludgy so I'm leaving an explicit note to find