zephyr_mirror: Truncate stream names to 30 characters.

(imported from commit 9973168227896dc8f1dc061b7970a503565856bf)

api/zephyr_mirror.py

@@ -73,6 +73,8 @@ def send_humbug(zeph):
     zeph['shortname'] = zeph['sender'].split('@')[0]
     if "subject" in zeph:
         zeph["subject"] = zeph["subject"][:60]
+    if "stream" in zeph:
+        zeph["stream"] = zeph["stream"][:30]
 
     for key in zeph.keys():
         if isinstance(zeph[key], unicode):