Use Trilogy#discard! when discard! called on TrilogyAdapter

Author: adrianna-chang-shopify

activerecord/lib/active_record/connection_adapters/trilogy_adapter.rb

@@ -207,7 +207,11 @@ def disconnect!
       end
 
       def discard!
-        self.connection = nil
+        super
+        unless connection.nil?
+          connection.discard!
+          self.connection = nil
+        end
       end
 
       def each_hash(result)