Show scheduled limit error.

Telegram/Resources/langs/lang.strings

@@ -298,6 +298,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "lng_error_nocopy_group" = "Sorry, copying from this group is disabled by admins.";
 "lng_error_nocopy_channel" = "Sorry, copying from this channel is disabled by admins.";
 "lng_error_nocopy_story" = "Sorry, the creator of this story disabled copying.";
+"lng_error_schedule_limit" = "Sorry, you can't schedule more than 100 messages.";
 "lng_sure_add_admin_invite" = "This user is not a member of this group. Add them to the group and promote them to admin?";
 "lng_sure_add_admin_invite_channel" = "This user is not a subscriber of this channel. Add them to the channel and promote them to admin?";
 "lng_sure_add_admin_unremove" = "This user is currently restricted or removed. Are you sure you want to promote them?";

Telegram/SourceFiles/apiwrap.cpp

@@ -559,6 +559,14 @@ void ApiWrap::sendMessageFail(
 			: tr::lng_error_noforwards_group(tr::now), kJoinErrorDuration);
 	} else if (error == u"PREMIUM_ACCOUNT_REQUIRED"_q) {
 		Settings::ShowPremium(&session(), "premium_stickers");
+	} else if (error == u"SCHEDULE_TOO_MUCH"_q) {
+		auto &scheduled = _session->scheduledMessages();
+		if (const auto item = scheduled.lookupItem(peer->id, itemId.msg)) {
+			scheduled.removeSending(item);
+		}
+		if (show) {
+			show->showToast(tr::lng_error_schedule_limit(tr::now));
+		}
 	}
 	if (const auto item = _session->data().message(itemId)) {
 		Assert(randomId != 0);