Remove references to ruby-plsql gem

Removed the oracle gem

We don't connect to the oracle database.

If I need to search for something other than `plsql`, `oci`, or `oracle`, let me know.

AFTER: remove `ruby-plsql` from the rpmspec
No, all the Oracle support is put in to a gem.  We could possibly push up to them, but I don't have Oracle installed for testing >_<