UI: Show error if Google account has no channels

UI/window-basic-settings-stream.cpp

@@ -424,7 +424,10 @@ static void get_yt_ch_title(Ui::OBSBasicSettings *ui,
 			if (IsYouTubeService(
 				    QT_TO_UTF8(ui->service->currentText()))) {
 				ui->connectedAccountText->setText(
-					QTStr("Auth.LoadingChannel.Error"));
+					ytAuth->GetLastError().isEmpty()
+						? QTStr("Auth.LoadingChannel.Error")
+						: QTStr("YouTube.AuthError.Text")
+							  .arg(ytAuth->GetLastError()));
 			}
 		}
 	}

UI/youtube-api-wrappers.cpp

@@ -156,6 +156,13 @@ bool YoutubeApiWrappers::GetChannelDescription(
 	if (!InsertCommand(url, "application/json", "", nullptr, json_out)) {
 		return false;
 	}
+
+	if (json_out["pageInfo"]["totalResults"].int_value() == 0) {
+		lastErrorMessage =
+			"No channel(s) available on selected account";
+		return false;
+	}
+
 	channel_description.id =
 		QString(json_out["items"][0]["id"].string_value().c_str());
 	channel_description.country =