Merge branch 'be_stable' into 'branch-0.3.1-xiaojun'

MS-240 fix unitttest build error

See merge request megasearch/milvus!229

Former-commit-id: 3bf03ba09f3fe6261dba260dab83ce9592fa6f42

cpp/unittest/index_wrapper/knowhere_test.cpp

@@ -5,11 +5,13 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 #include <gtest/gtest.h>
+#include <easylogging++.h>
 
 #include <wrapper/knowhere/vec_index.h>
 
 #include "utils.h"
 
+INITIALIZE_EASYLOGGINGPP
 
 using namespace zilliz::milvus::engine;
 using namespace zilliz::knowhere;