fix segfault if ngx_read_file() will fail
diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 8063648..1e80a39 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -251,6 +251,7 @@
                    "http file cache fd: %d", of.fd);
 
     c->file.fd = of.fd;
+    c->file.log = r->connection->log;
 
     c->buf = ngx_create_temp_buf(r->pool, c->body_start);
     if (c->buf == NULL) {