Fix timeline streaming stopping for multiple sessions instead of one (m…

…astodon#17259)

* Fix timeline streaming stopping for multiple sessions instead of one

Fixes mastodon#17256.

In updating the code for a newer version of node-redis, mastodon#17183 also broke
redis subscription management when multiple streaming clients subscribe to the
same channel.

This commit restores the redis subscription management code.

* Let node-redis actually handle the subscriptions

streaming/index.js

@@ -197,10 +197,12 @@ const startWorker = async (workerId) => {
 
  /**
  * @param {string} channel
+ * @param {function(string): void} callback
  */
- const unsubscribe = (channel) => {
+ const unsubscribe = (channel, callback) => {
+ log.silly(`Removing listener for ${channel}`);
 
- redisSubscribeClient.unsubscribe(channel);
+ redisSubscribeClient.unsubscribe(channel, callback);
  };
 
  const FALSE_VALUES = [