typo

Signed-off-by: Ngroot <yihua.mo@zilliz.com>

CHANGELOG.md

@@ -45,7 +45,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#1535 Degradation searching performance with metric_type: binary_idmap
 -   \#1556 Index file not created after table and index created
 -   \#1560 Search crashed with Super-high dimensional binary vector
--   \#1571 Meta engine type become IDMAP after drop index for BINARY table
+-   \#1571 Meta engine type become IDMAP after dropping index for BINARY table
 
 ## Feature
 -   \#216 Add CLI to get server info