Remove ';' in generated query

[Yopai]

Hi,

=== Context
Phinx :) for this work.

I'm writing an Adapter for PDO-OCI.

I'm getting blocked by some things that should be fixed in

=== Observed behaviour
In the PDO adapter, migrated generates a query with a semi-colon at the end. ';' is a query separator, and is not allowed by PDO-OCI (ORA-00911 - Invalid character)

=== Expected behaviour
I would ask to remove this ';', given that it won't change anything for other databases.

I have patched it manually (by overriding it in the OCIAdapter I have created) for now, I will push a PR for that when I'll have some time.