Fix /var configuration in .gitignore
Fix /var configuration in .gitignore

A better fix would probably be to move the DB elsewhere.

But at least, this change is required to make the demo work out of the box. If not, the `var/` directory is not added when doing `git add .` after creating the project with `composer create-project`, which is not what we want.
javiereguiluz/symfony-demo,javiereguiluz/symfony-demo,bocharsky-bw/symfony-demo,Codeception/symfony-demo,TomasVotruba/symfony-demo,voronkovich/symfony-demo,voronkovich/symfony-demo,yceruto/symfony-demo,symfony/symfony-demo,yceruto/symfony-demo,TomasVotruba/symfony-demo,symfony/symfony-demo,javiereguiluz/symfony-demo,Codeception/symfony-demo,voronkovich/symfony-demo,TomasVotruba/symfony-demo,bocharsky-bw/symfony-demo,symfony/symfony-demo,Codeception/symfony-demo,yceruto/symfony-demo,bocharsky-bw/symfony-demo