Use 'rpm' for retracted to make the problem string match

mlschroe · mlschroe · commit 3026a7ad5e87 · 2020-09-11T12:23:34.000+02:00
diff --git a/test/testcases/blacklist/retracted.t b/test/testcases/blacklist/retracted.t
@@ -6,7 +6,7 @@ repo available 0 testtags <inline>
 #>=Pkg: B 2 1 noarch
 #>=Prv: retracted-patch-package()
 
-system unset * system
+system unset rpm system
 
 job blacklist provides retracted-patch-package()
 job install name patch
