- return false when filter is applied

bigbluebutton-web/grails-app/conf/BigBlueButtonFilters.groovy

@@ -30,8 +30,10 @@ class BigBlueButtonFilters {
   	serviceUnavailable(controller:'api',action:'(create|join|isMeetingRunning|end|getMeetingInfo|getMeetings|enter|signOut)') {
   		before = {
         System.out.println("enter filter")
-  			if (keepAliveService.isDown())
+  			if (keepAliveService.isDown()) {
   				response.sendError(503, "BigBlueButton")
+					return false
+  			}
   		}
   	}
   }