fix(streaming): req.scopes can be nullable (#16823)

When checking for required OAuth scopes, an unexpected error could
happen due to missing (null-y) req.scopes. This commit fixes that by
checking if req.scopes are present before checking if any required
scopes are present, otherwise it skips that straight to rejection.

streaming/index.js

@@ -430,7 +430,7 @@ const startWorker = (workerId) => {
       requiredScopes.push('read:statuses');
     }
 
-    if (requiredScopes.some(requiredScope => req.scopes.includes(requiredScope))) {
+    if (req.scopes && requiredScopes.some(requiredScope => req.scopes.includes(requiredScope))) {
       resolve();
       return;
     }