Fix quickaccess active indicator for folders with spaces

[juliushaertl]

Fixes a javascript error and missing active indicator on favorite folders with spaces:

Syntax error, unrecognized expression: li[data-id=-folder with spaces]

Steps to reproduce:

1. Create a folder named "test with spaces"
2. Add the folder to the favorites
3. Unfold the favorites entry in the left navigation
4. Click the "test with spaces" entry

From https://sentry.rullzer.com/sentry/nextcloud/issues/34

[skjnldsv]

Nice catch!