Add missing +

Thanks to @LucaColonnello for this catch (#39)

Author: superhawk610

app/config.js

@@ -64,7 +64,7 @@ var startConfig = () => {
         console.log('')
         console.log('Configuration updated! To get started, just run\n' +
           '\n' +
-          '  multicast start'
+          '  multicast start' +
           '\n')
       })
       rl.close()