HPCC-8697 Build errors on EE on Ubuntu 12.10

Stricter template checking is giving errors in javahash.tpp. This only affects
legacy thor builds, it seems.

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #3912 from richardkchapman/clangers

HPCC-8697 Build errors on EE on Ubuntu 12.10

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>