Force re-creation of PLT for OTP library

PLEASE DO NOT MERGE.
This is only for cleaning up the PLT file.

cf. https://github.com/basho/riak_cs/pull/848#issuecomment-42474222
Merge pull request #859 from basho/dummy/clean-plt

[DO NOT MERGE] Force re-creation of PLT for OTP library

Reviewed-by: ksauzz