fix ci

Author: wuxianrong

CMakeLists.txt

@@ -175,9 +175,9 @@ set(GMOCK_INCLUDE_DIR ${INSTALL_INCLUDEDIR})
 
 ExternalProject_Add(gflags
   URL
-  https://github.com/gflags/gflags/archive/refs/tags/v2.2.2.tar.gz
+  https://github.com/gflags/gflags/releases/download/v2.2.1/gflags-2.2.1.tar.gz.asc 
   URL_HASH
-  MD5=1a865b93bacfa963201af3f75b7bd64c
+  MD5=de19c39cfea251921dc13f5607e0b233
   DOWNLOAD_NO_PROGRESS
   1
   UPDATE_COMMAND