Expect that the app executable ends in .exe

Electron/WebPublic/js/clean-electron.js

@@ -169,7 +169,7 @@ function run (_opts) {
 		const opts=DEFAULTS;
 		Object.assign (opts,_opts);
 
-		const server=spawn ('./'+opts.app,['--port',opts.port],{stdio: 'inherit'});
+		const server=spawn ('./'+opts.app+'.exe',['--port',opts.port],{stdio: 'inherit'});
 		server.on ('close',code => {
 			if (code!==0 && code!==null)
 				console.log ('iTasks exited with exit code '+code);