WatermarkAlignment doesn't work for NumericUpDown #4189
Description
Describe the bug
The WatermarkAlignment for NumericUpDown will not change because the HorizontalContentAlignment is set to Right.
Reported by @RejectKid on Gitter.
Expected behavior
The WatermarkAlignment should work.
Actual behavior
Nothing happens.
Environment
MahApps.Metro version: v2.4.7
