Conversation: add "You left the conversation." string

Follow up to https://review.jami.net/c/jami-client-qt/+/30295

GitLab: #1932

Change-Id: Ic6e78bd3384c9b825a7fd3bc82409d3e6df2b721

src/libclient/api/interaction.h

@@ -288,6 +288,9 @@ getContactInteractionString(const QString& authorUri, const ContactAction& actio
         }
         return QObject::tr("%1 has joined the conversation.").arg(authorUri);
     case ContactAction::LEAVE:
+        if (authorUri.isEmpty()) {
+            return QObject::tr("You left the conversation.");
+        }
         return QObject::tr("%1 has left the conversation.").arg(authorUri);
     case ContactAction::BANNED:
         return QObject::tr("%1 was blocked from the conversation.").arg(authorUri);