Do not build 32bit skeletons lib and check-converter
Do not build 32bit skeletons lib and check-converter

when the 32bit build is dislabed.

On MacOS with Xcode 9.0 the make check fails because the ar
cannot build empty static libraries

Fixes #228

khmseu/asn1c,khmseu/asn1c,mouse07410/asn1c,khmseu/asn1c,mouse07410/asn1c,mouse07410/asn1c,khmseu/asn1c,mouse07410/asn1c