Fix narrowing to pm-with lists not in alphabetical order.

Previously if you narrowed to
"pm-with:wdaher@humbughq.com,jbarnold@humbughq.com", you'd always get
no results because our filter was comparing your query against
message.reply_to, which is sorted in alphabetical order.

(imported from commit 40dc78640f3b010f11312176cfcf3c331fdf3337)

zephyr/static/js/narrow.js

@@ -229,7 +229,7 @@ function build_filter(operators_mixed_case) {
 
             case 'pm-with':
                 if ((message.type !== 'private') ||
-                    (message.reply_to.toLowerCase() !== operand))
+                    message.reply_to.toLowerCase() !== operand.split(',').sort().join(','))
                     return false;
                 break;