Fix logs view in superuser panel

This seems to have been broken ever since we moved to syslog

endpoints/api/superuser.py

@@ -47,14 +47,14 @@ class SuperUserGetLogsForService(ApiResource):
         abort(404)
 
       try:
-        with open(app.config['SYSTEM_SERVICE_LOGS_PATH'] % service, 'r') as f:
-          logs = f.read()
+        with open(app.config['SYSTEM_LOGS_FILE'], 'r') as f:
+          logs = f.readlines()
       except Exception as ex:
         logger.exception('Cannot read logs')
         abort(400)
 
       return {
-        'logs': logs
+        'logs': '\n'.join([log for log in logs if log.find(service + '[') >= 0])
       }
 
     abort(403)