Reset pniCredential when our E164 changes

Co-authored-by: Fedor Indutny <79877362+indutny-signal@users.noreply.github.com>

ts/models/conversations.ts

@@ -1873,6 +1873,11 @@ export class ConversationModel extends window.Backbone
     if (e164 !== oldValue) {
       this.set('e164', e164 || undefined);
 
+      // When our own number has changed - reset pniCredential
+      if (isMe(this.attributes)) {
+        this.set({ pniCredential: null });
+      }
+
       if (oldValue && e164) {
         this.addChangeNumberNotification(oldValue, e164);
       }