route_handler: remove auto-HEAD

src/kemal/route_handler.cr

@@ -21,7 +21,7 @@ module Kemal
     # a corresponding `HEAD` route.
     def add_route(method : String, path : String, &handler : HTTP::Server::Context -> _)
       add_to_radix_tree method, path, Route.new(method, path, &handler)
-      add_to_radix_tree("HEAD", path, Route.new("HEAD", path) { }) if method == "GET"
+      # add_to_radix_tree("HEAD", path, Route.new("HEAD", path) { }) if method == "GET"
     end
 
     # Looks up the route from the Radix::Tree for the first time and caches to improve performance.