Ignore files which are modified by our tests

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

.gitignore

@@ -159,3 +159,6 @@ tests/acceptance/vendor/
 composer.phar
 /lib/composer/bin
 /vendor-bin/**/vendor
+
+./.htaccess
+core/js/mimetypelist.js