[tlbuild] icu-57.1 trial builds in tl

[Apostolos Syropoulos]

I had no problem on OpenIndiana. However, I got

FAIL: tests/upmendex.test
============================================================================
Testsuite summary for upmendex (TeX Live) 0.50
============================================================================
# TOTAL: 1
# PASS:  0
# SKIP:  0
# XFAIL: 0
# FAIL:  1
# XPASS: 0
# ERROR: 0


A.S.
-- 
Apostolos Syropoulos
Xanthi, GREECE