changelog: Added fixes for issues zulip#247, zulip#259, zulip#266.

Author: sumanthvrao

CHANGELOG.md

@@ -20,6 +20,8 @@
 - Avoid crash in rare case of empty message content
 - Set terminal locale to `utf-8` by default which removes issues with rendering double width characters.
 - Avoid crash on receiving multiple starred-message events
+- Avoid crash on sending messages in narrows with no previous messages
+- Change current narrow label for empty narrows with no previous messages
 
 ### Infrastructure changes
 - Minimized initial registration & communication with zulip server