Optimize some regex matching (#15528)

* Use Regex#match?

* Replace =~ too

* Avoid to call match? from Nil

* Keep value of Regexp.last_match

app/services/search_service.rb

@@ -72,7 +72,7 @@ class SearchService < BaseService
   end
 
   def url_query?
-    @resolve && @query =~ /\Ahttps?:\/\//
+    @resolve && /\Ahttps?:\/\//.match?(@query)
   end
 
   def url_resource_results