wallpapers/image: fix potential dead loop in PackageFinder
When a symlink points to its parent folder, a dead loop can exist in PackageFinder because it doesn't de-duplicate folder paths.
When a symlink points to its parent folder, a dead loop can exist in PackageFinder because it doesn't de-duplicate folder paths.
mentioned in commit 6f5a1dc9
mentioned in commit f744e705
mentioned in commit dd3dd0c7
mentioned in commit e8e5ef2e
mentioned in commit 80c7d1fa