[Chessx-users] Bugfix 1.6.4 for Mac OS / Qt6 installations

[jens-chessx <jen...@gm...>]

Dear Chessx Users,

I just pushed a version 1.6.4 fixing a bug which only appears under Qt6 -
engine options were not stored correctly.
As only Mc OS binaries use Qt6, I only updated the Mac Installer.

Jens