adjust an error message in a test

Author: ThomasBreuer

tst/testbugfix/2007-07-02-t00180.tst

@@ -1,6 +1,6 @@
 # 2007/07/02 (SK)
 gap> GeneratorsOfRing(Rationals);
-Error, cannot compute elements list of infinite domain <V>
+Error, cannot compute elements list over infinite domain <F>
 gap> GeneratorsOfRingWithOne(Rationals);
 Error, no method found! For debugging hints type ?Recovery from NoMethodFound
 Error, no 2nd choice method found for `GeneratorsOfRingWithOne' on 1 arguments