Symfony ignore AppleDouble
The folder is created not by Apple but by NAS which you are using probably. Look at this FAQ
So if you use Netatalk you should probably look at its docs. Same folders are created by RedyNAS. But the common pattern as I understood is to run command from terminal that @Valentas described. And then remove the folders recursively.
If you have to hold folders and make Symfony work you should modify the value of Finder::vcsPatterns. As the property is static you can add the following code to the app/console (or bin/console):
...Finder::addVCSPattern('.AppleDouble');$kernel = new AppKernel($env, $debug);...