Reset multi selection when conversation is deleted/changed

js/models/conversations.js

@@ -2526,6 +2526,7 @@
     },
 
     deleteMessages() {
+      this.resetMessageSelection();
       if (this.isPublic()) {
         Whisper.events.trigger('showConfirmationDialog', {
           message: i18n('deletePublicConversationConfirmation'),

js/views/conversation_view.js

@@ -755,6 +755,7 @@
       this.lastActivity = Date.now();
 
       this.model.updateLastMessage();
+      this.model.resetMessageSelection();
 
       if (this.model.isRss()) {
         $('.compose').hide();