Fixed #3925

Also updated port local variable to be a Number, since all of the
conditional checks assume it is a number, when all along it has
been a string.... heh.

src/webserver.js

@@ -121,7 +121,7 @@ function cacheStaticFiles(callback) {
 }
 
 function listen(callback) {
-	var port = nconf.get('port');
+	var port = parseInt(nconf.get('port'), 10);
 
 	if (Array.isArray(port)) {
 		if (!port.length) {
@@ -138,7 +138,7 @@ function listen(callback) {
 		}
 	}
 
-	if (port !== 80 && port !== 443 && nconf.get('use_port') === false) {
+	if ((port !== 80 && port !== 443) || nconf.get('trust_proxy') === true) {
 		winston.info('Enabling \'trust proxy\'');
 		app.enable('trust proxy');
 	}