UI: Fix Auto-Config Wizard for custom server with no stream key

The Auto-Configuration Wizard cannot progress when selecting a custom
service that does not require a stream key. Since we have no way to
validate if a custom service requires a stream key, we should just not
require a stream key is custom service is selected. To fix this, check
if a custom service has not been selected when checking if the stream
key is empty.

Co-authored-by: Ryan Foster <[email protected]>

UI/window-basic-auto-config.cpp

@@ -852,11 +852,11 @@ void AutoConfigStreamPage::UpdateServerList()
 
 void AutoConfigStreamPage::UpdateCompleted()
 {
+	const bool custom = IsCustomService();
 	if (ui->stackedWidget->currentIndex() == (int)Section::Connect ||
-	    (ui->key->text().isEmpty() && !auth)) {
+	    (ui->key->text().isEmpty() && !auth && !custom)) {
 		ready = false;
 	} else {
-		bool custom = IsCustomService();
 		if (custom) {
 			ready = !ui->customServer->text().isEmpty();
 		} else {