Docs: fix changelog merge

Author: imotov

docs/CHANGELOG.asciidoc

@@ -179,19 +179,6 @@ Machine Learning::
 
 Add validation that geohashes are not empty and don't contain unsupported characters ({pull}30376[#30376])
 
-[[release-notes-6.3.1]]
-== Elasticsearch version 6.3.1
-
-//[float]
-//=== New Features
-
-//[float]
-//=== Enhancements
-
-[float]
-=== Bug Fixes
-
-Reduce the number of object allocations made by {security} when resolving the indices and aliases for a request ({pull}30180[#30180])
 Rollup::
 * Validate timezone in range queries to ensure they match the selected job when
 searching ({pull}30338[#30338])