Drop --fail-missing argument for dh_install, default since debhelper compat 12

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

debian/rules

@@ -23,7 +23,7 @@ override_dh_auto_test:
 
 override_dh_install:
 	rm -f debian/tmp/usr/lib/*/*.la
-	dh_install --fail-missing
+	dh_install
 	dh_apparmor -plibtraprain-0-tests \
 		--profile-name=usr.lib.installed-tests.traprain.test-mock-service
 	dh_apparmor -ptraprain-guidance-ui \