[test] fix wrong t/op/stringu.t testcount --without-icu
[test] fix wrong t/op/stringu.t testcount --without-icu

this test works now also without ICU.
improve the wording also.

youprofit/parrot,tkob/parrot,FROGGS/parrot,tkob/parrot,youprofit/parrot,parrot/parrot,FROGGS/parrot,tkob/parrot,youprofit/parrot,tkob/parrot,parrot/parrot,tkob/parrot,tkob/parrot,FROGGS/parrot,parrot/parrot,FROGGS/parrot,youprofit/parrot,youprofit/parrot,FROGGS/parrot,FROGGS/parrot,tkob/parrot,youprofit/parrot,parrot/parrot,FROGGS/parrot,parrot/parrot,tkob/parrot,youprofit/parrot,youprofit/parrot,FROGGS/parrot