tools: fix md5 hash for ICU 68.1 src
Correct md5sum hash for the tarball version of the ICU 68.1 source. The previously recorded md5sum hash was for the zip version.
Fixes: https://github.com/nodejs/node/issues/36776
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines