feat(chatlog): Disable join and leave system messages based on setting

src/widget/form/groupchatform.cpp

@@ -231,13 +231,17 @@ void GroupChatForm::updateUserNames()
 
 void GroupChatForm::onUserJoined(const ToxPk& user, const QString& name)
 {
+    if (settings.getShowGroupJoinLeaveMessages()) {
         addSystemInfoMessage(QDateTime::currentDateTime(), SystemMessageType::userJoinedGroup, {name});
+    }
     updateUserNames();
 }
 
 void GroupChatForm::onUserLeft(const ToxPk& user, const QString& name)
 {
+    if (settings.getShowGroupJoinLeaveMessages()) {
         addSystemInfoMessage(QDateTime::currentDateTime(), SystemMessageType::userLeftGroup, {name});
+    }
     updateUserNames();
 }