Merge branch 'tz/test-prepare-gnupghome'

Tests did not set up GNUPGHOME correctly, which is fixed but some
flaky tests are exposed in t1016, which needs to be addressed
before this topic can move forward.

* tz/test-prepare-gnupghome:
  t/lib-gpg: call prepare_gnupghome() in GPG2 prereq
  t/lib-gpg: add prepare_gnupghome() to create GNUPGHOME dir

Author: gitster

t/lib-gpg.sh

@@ -71,6 +71,7 @@ test_lazy_prereq GPG2 '
 		exit 1
 		;;
 	*)
+		prepare_gnupghome &&
 		(gpgconf --kill all || : ) &&
 
 		# NEEDSWORK: prepare_gnupghome() should definitely be