Fix the delete messages button to not break the conversation

_locales/en/messages.json

@@ -1053,7 +1053,7 @@
       "Confirmation dialog text that asks the user if they really wish to delete the public channel messages locally. Answer buttons use the strings 'ok' and 'cancel'. The deletion is permanent, i.e. it cannot be undone."
   },
   "deleteConversationConfirmation": {
-    "message": "Permanently delete this conversation?",
+    "message": "Permanently delete the messages in this conversation?",
     "description":
       "Confirmation dialog text that asks the user if they really wish to delete the conversation. Answer buttons use the strings 'ok' and 'cancel'. The deletion is permanent, i.e. it cannot be undone."
   },

js/models/conversations.js

@@ -2450,8 +2450,8 @@
         });
       } else {
         Whisper.events.trigger('showConfirmationDialog', {
-          message: i18n('deleteContactConfirmation'),
-          onOk: () => ConversationController.deleteContact(this.id),
+          message: i18n('deleteConversationConfirmation'),
+          onOk: () => this.destroyMessages(),
         });
       }
     },