(bug) gathering-heatbeat markers arrive at the client with an unsafe integer value for user_guid

gathering-heartbeat markers are received with unsafe integer values where guid entities are sent as strings

{
  "user_guid":994952798468575247,
  "entity_type":"group",
  "entity_guid":"997822291385520137",
  "marker":"gathering-heartbeat",
  "updated_timestamp":1563367071,
  "disabled":false,
  "read_timestamp":null
}

This gives unexpected results if the value is use in Javascript