- Bump version: 9.23.53 → 9.23.54

- Fixed condition for GRUB_DISABLE_LINUX_UUID="true"
The grub config parameter GRUB_DISABLE_LINUX_UUID must only
be set if the device persistence setting is not UUID. However,
in kiwi UUID device names are the default and doesn't have to
be expressed explicitly. Therefore the condition to check
for different than 'by-uuid' is wrong for the default case were
no device persistence setting exists. This results in a wrong
grub option to be set. This commit fixes it in a way to disable
UUID device names in grub if the only other device persistency
setting in kiwi named: 'by-label' is explicitly configured.
This Fixes #1842

- Added force_trailing_slash argument to sync_data
A speciality of the rsync tool is that it behaves differently
if the given source_dir ends with a '/' or not. If it ends
with a slash the data structure below will be synced to the
target_dir. If it does not end with a slash the source_dir
and its contents are synced to the target_dir. For example:
source
└── some_data
1. $ rsync -a source target
target
└── source
└── some_data
2. $ rsync -a source/ target
target
└── some_data
The parameter force_trailing_slash in the DataSync::sync_data