Read HKLM fallback from cross registry view
* src/addin-options.cpp (open-gpgolconfig): Do not pass w64 again. * src/common.cpp (CROSS_ACCESS): New define. (_readRegStr): Helper for readRegStr. (readRegStr): More explicit fallbacks.
This should be more robust to handle cases where either
HKLM is set up as 32 bit registry key or as 64 bit registry
key.