Restore streaming API output format (#4100)

* Restore streaming API output format

Regression from #4090

* Remove whitespace

streaming/index.js

@@ -264,9 +264,10 @@ const startWorker = (workerId) => {
       const transmit = () => {
         const now            = new Date().getTime();
         const delta          = now - queued_at;
+        const encodedPayload = typeof payload === 'number' ? payload : JSON.stringify(payload);
 
-        log.silly(req.requestId, `Transmitting for ${req.accountId}: ${event} ${payload} Delay: ${delta}ms`);
-        output(event, payload);
+        log.silly(req.requestId, `Transmitting for ${req.accountId}: ${event} ${encodedPayload} Delay: ${delta}ms`);
+        output(event, encodedPayload);
       };
 
       if (notificationOnly && event !== 'notification') {
@@ -282,7 +283,7 @@ const startWorker = (workerId) => {
             return;
           }
 
-          const unpackedPayload  = JSON.parse(payload);
+          const unpackedPayload  = payload;
           const targetAccountIds = [unpackedPayload.account.id].concat(unpackedPayload.mentions.map(item => item.id));
           const accountDomain    = unpackedPayload.account.acct.split('@')[1];