Add davfs2 secrets file to blacklist

[jose1711]

The files holds credentials to WebDAV servers in plaintext
hence it's probably a good idea to limit access to them.

[rusty-snake]

@jose1711 thats good, but I think that we have some profile which need to access these files.
Or am I mistaken? If not try to find out which are this.

[jose1711]

the only program i can think of is nautilus. but odds are that it uses its own file for auth stuff

[rusty-snake]

Ok, you're right. dnf repoquery --alldeps --whatrequires davfs2 doesn have output.