Merge branch 'branch-0.3.1-yuncong' into 'branch-0.3.1-yuncong'

Change threshold to 20

See merge request megasearch/milvus!182

Former-commit-id: c298e5af365ea61946f976cdc8f035e1c1d0e412

cpp/conf/server_config.template

@@ -34,5 +34,5 @@ cache_config:           # cache configure
 
 engine_config:
   nprobe: 10
-  nlist: 16381
-  use_blas_threshold: 10
\ No newline at end of file
+  nlist: 16384
+  use_blas_threshold: 20
\ No newline at end of file