gopkg: remove deprecated ImportFromBinary field
gopkg: remove deprecated ImportFromBinary field

This field was removed from loader in
https://github.com/golang/tools/commit/9c57c19a58835b00c0e3e283952087842242e49b

Change-Id: Ica2b1ac4d506f30390358b2f95ec37ea0b5e633a

vanadium/go.devtools,vanadium/go.devtools,vanadium/go.devtools