tests: really don't run tests in cross-compilation

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

diff -durN gnupg2-2.0.29.orig/tests/Makefile.am gnupg2-2.0.29/tests/Makefile.am
--- gnupg2-2.0.29.orig/tests/Makefile.am	2015-09-08 14:39:24.000000000 +0200
+++ gnupg2-2.0.29/tests/Makefile.am	2015-12-16 18:27:55.778227183 +0100
@@ -64,6 +64,7 @@
 asschk_SOURCES = asschk.c
 
 
+if RUN_GPG_TESTS
 all-local: inittests.stamp
 
 clean-local:
@@ -72,4 +73,5 @@
 inittests.stamp: inittests
 	srcdir=$(srcdir) $(TESTS_ENVIRONMENT) $(srcdir)/inittests
 	echo timestamp >./inittests.stamp
+endif # RUN_GPG_TESTS
 
diff -durN gnupg2-2.0.29.orig/tests/pkits/Makefile.am gnupg2-2.0.29/tests/pkits/Makefile.am
--- gnupg2-2.0.29.orig/tests/pkits/Makefile.am	2015-09-01 08:52:21.000000000 +0200
+++ gnupg2-2.0.29/tests/pkits/Makefile.am	2015-12-16 18:44:06.422655594 +0100
@@ -52,6 +52,7 @@
 
 DISTCLEANFILES = pubring.kbx~ random_seed
 
+if RUN_GPG_TESTS
 all-local: inittests.stamp
 
 clean-local:
@@ -71,5 +72,5 @@
            elif test $$? -eq 77; then echo "- SKIP $$tst"; \
 	   fi; \
          done
-
+endif # RUN_GPG_TESTS