Rpc server use epoll (#687)

Co-authored-by: 杨赫然 <heran.yang@seafile.com>

server/seaf-server.c

@@ -1077,6 +1077,8 @@ static void start_rpc_service (const char *seafile_dir,
         exit (1);
     }
 
+    rpc_server->use_epoll = TRUE;
+
     if (searpc_named_pipe_server_start(rpc_server) < 0) {
         seaf_warning ("Failed to start rpc server.\n");
         exit (1);