Set 64 and 32 bit architecture for win builds
Set 64 and 32 bit architecture for win builds

This should enforce 64 bit builds on AppVeyor and hopefully resolves
issues with out of memory errors when importing big images on
windows.

codarchlab/idai-field-client,codarchlab/idai-field-client,codarchlab/idai-field-client,codarchlab/idai-field-client