[multiple] add assert after malloc in two spots

add missing assert after malloc in two spots to detect malloc failure
(unlikely)

src/mod_dirlisting.c

@@ -1077,6 +1077,7 @@ static int http_read_directory(handler_ctx * const p) {
 		}
 		dirls_entry_t * const tmp = list->ent[list->used++] =
 		  (dirls_entry_t*) malloc(sizeof(dirls_entry_t) + 1 + dsz);
+		force_assert(tmp);
 		tmp->mtime = st.st_mtime;
 		tmp->size  = st.st_size;
 		tmp->namelen = dsz;

src/mod_mysql_vhost.c

@@ -68,6 +68,7 @@ static void* mod_mysql_vhost_connection_data(request_st * const r, void *p_d)
 
 	if (c) return c;
 	c = calloc(1, sizeof(*c));
+	force_assert(c);
 
 	c->server_name = buffer_init();
 	c->document_root = buffer_init();