Merge pull request #843 from hiptest/fix-327-concern-cause-app-to-connect-to-db

Better implementation to test if connection to db is active

Author: booleanbetrayal

app/models/devise_token_auth/concerns/user.rb

@@ -99,11 +99,7 @@ def tokens_has_json_column_type?
     end
 
     def database_exists?
-      ActiveRecord::Base.connection
-    rescue ActiveRecord::NoDatabaseError
-      false
-    else
-      true
+      ActiveRecord::Base.connection_pool.with_connection { |con| con.active? } rescue false
     end
   end