Engine: Wrong case for Sysprep UiLanguage

The replace of "$UiLangues$" in SysprepHandler is skipped because of the
wrong case (should be UILanguage)
Also setting the $SetupUiLanguageUiLanguage$ to UILanguage.

Change-Id: Iaf4a37e4607af7238076050213b9c5c5b6914b74
Signed-off-by: Shahar Havivi <shaharh@redhat.com>