Only run tests when building architecture-dependent packages

The tests aren't so interesting that we want to run them again when
splitting -arch/-indep builds.

debian/rules

@@ -38,11 +38,14 @@ endif
 override_dh_auto_configure:
 	dh_auto_configure -- $(configure_options)
 
-override_dh_auto_test:
+override_dh_auto_test-arch:
 ifeq (,$(filter nocheck,$(DEB_BUILD_OPTIONS)))
 	debian/test.sh
 endif
 
+override_dh_auto_test-indep:
+	:
+
 override_dh_auto_install:
 	dh_auto_install
 ifeq (,$(filter nodoc,$(DEB_BUILD_PROFILES)))