Only show checkbox if there is more than one user involved take 2

Only show checkbox if there is more than one user involved take 2

Fix for real this time: convert string to array before checking its length

diff --git a/assets/javascripts/discourse/components/bcc-checkbox.js.es6 b/assets/javascripts/discourse/components/bcc-checkbox.js.es6
index 32507a8..470aa44 100644
--- a/assets/javascripts/discourse/components/bcc-checkbox.js.es6
+++ b/assets/javascripts/discourse/components/bcc-checkbox.js.es6
@@ -11,7 +11,7 @@ export default Component.extend({
       return (
         this.currentUser.staff &&
         this.creatingPrivateMessage &&
-        (this.targetUsernames || "").length > 1
+        (this.targetUsernames || "").split(",").length > 1
       );
     }
   )

GitHub sha: d205b9ce