Docs: fixed typo

Closes #7544

docs/reference/index-modules/query-cache.asciidoc

@@ -17,7 +17,7 @@ results from older indices will be served directly from the cache.
 [IMPORTANT]
 ==================================
 
-For now, the query cache will only  only cache the results of search requests
+For now, the query cache will only cache the results of search requests
 where <<count,`?search_type=count`>>, so it will not cache `hits`,
 but it will cache `hits.total`,  <<search-aggregations,aggregations>>, and
 <<search-suggesters,suggestions>>.