include gpgme source for context.h
include gpgme source for context.h

This should go away once gpgme_signers_count() is put in use.
https://dev.guardianproject.info/issues/1549

guardianproject/gnupg-for-java,HellUnit/gnupg-for-java,guardianproject/gnupg-for-java,HellUnit/gnupg-for-java,HellUnit/gnupg-for-java,eighthave/gnupg-for-java,eighthave/gnupg-for-java,guardianproject/gnupg-for-java,eighthave/gnupg-for-java,HellUnit/gnupg-for-java