FIX: redirect to original URL after social signup

lib/auth/result.rb

@@ -69,6 +69,8 @@ class Auth::Result
                  email_valid: !!email_valid,
                  omit_username: !!omit_username }
 
+      result[:destination_url] = destination_url if destination_url.present?
+
       if SiteSetting.enable_names?
         result[:name] = User.suggest_name(name || username || email)
       end