#1329 MUI.nsh error since r7486

[Marius Negrutiu]

Commit r7486 "Use native IntPtrCmpU" has an unexpected side effect.
As part of the change, LogicLib.nsh no longer includes Util.nsh
This leads to errors when building installers that use the legacy MUI.nsh
Error flow:

1. !include MUI.nsh
2. !insertmacro MUI_PAGE_FINISH
3. MUI_PAGE_FINISH expands macro MUI_FUNCTION_FINISHPAGE (Contrib\Modern UI\System.nsh)
4. macro invokes ${If} ${IsHighContrastModeActive}
5. IsHighContrastModeActive is undefined because Util.nsh is no longer included
6. Build fails with message !insertmacro: macro "_If" requires 4 parameter(s), passed 2!
   Thanks.

[Anders]

Thank you