Skip authentication if API key is empty

Author: lacek

app/controllers/github_hook_controller.rb

@@ -45,7 +45,7 @@ def update_repository(logger)
 
   def check_enabled
     User.current = nil
-    unless Setting.sys_api_enabled? && params[:key].to_s == Setting.sys_api_key
+    unless Setting.sys_api_enabled? && (Setting.sys_api_key.empty? || params[:key].to_s == Setting.sys_api_key)
       render :text => 'Access denied. Repository management WS is disabled or key is invalid.', :status => 403
       return false
     end