Add confirmation message for banning too many users at once

Author: allen0099

Telegram/Resources/langs/lang.strings

@@ -2618,6 +2618,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "lng_group_requests_none_channel" = "There are no pending join requests.";
 "lng_group_requests_dismiss_all_confirm" = "Are you sure you want to dismiss all pending join requests?";
 "lng_group_requests_ban_all_confirm" = "Are you sure you want to ban all users who requested to join?";
+"lng_group_requests_ban_too_much_users" = "You cannot ban so many users at once. Try dismissing them instead.";
 
 "lng_channel_public_link_copied" = "Link copied to clipboard.";
 "lng_context_about_private_link" = "This link will only work for members of this chat.";

Telegram/SourceFiles/boxes/peers/edit_peer_requests_box.cpp

@@ -484,6 +484,14 @@ void RequestsBoxController::banAllRequests() {
 		return;
 	}
 
+	if (count >= 20) {
+		delegate()->peerListUiShow()->showBox(Ui::MakeConfirmBox({
+			.text = tr::lng_group_requests_ban_too_much_users(tr::now),
+			.inform = true
+		}));
+		return;
+	}
+
 	const auto guard = base::make_weak(this);
 	delegate()->peerListUiShow()->showBox(Ui::MakeConfirmBox({
 		.text = tr::lng_group_requests_ban_all_confirm(tr::now),