fix: add missing type

The countdownactive field of the RemoteType was missed in a recent
merge. It is being added back here.

src/types/custom.d.ts

@@ -106,6 +106,7 @@ declare global {
         remotevars: Record<string, string>;
         status: RemoteStatusTypeStrs;
         connecttimeout: number;
+        countdownactive: boolean;
         errorstr: string;
         installstatus: string;
         installerrorstr: string;