Add port number fallback

A bug somewhere leads to opts.connect having null in the port field

lib/nntp.js

@@ -89,6 +89,7 @@ function NNTP(opts, rawSpeedTracker) {
 		readableHighWaterMark: 0, // disable buffering
 		writableHighWaterMark: 1 // Node 20 seems to go wonky with a value of 0, so use 1 instead
 	}, opts.connect);
+	if (!connectOpts.port) connectOpts.port = opts.secure ? 563 : 119;
 	// although the feature was added in node 12.10.0, it's crashy on Linux until 13.13.0 / 12.16.3
 	// reported as unstable on 15.7.0, so we'll disable it everywhere until we get more info on it: https://github.com/animetosho/Nyuu/issues/87
 	var supportsOnread = false;