Prevent crash on `migrate:make`
Prevent crash on `migrate:make`

Fixes error introduced in 1d27fb8. `template` fails if passed a `null` second argument.

Fixes #1385

Atlantis-Software/knex,statyan/knex,tgriesser/knex,wubzz/knex,carragom/knex,statyan/knex,WaltRock/knex,wubzz/knex,abegines/knex,tgriesser/knex,noodle/knex,tgriesser/knex,CorvusCorrax/knex,CorvusCorrax/knex,Atlantis-Software/knex,abegines/knex,WaltRock/knex,carragom/knex,noodle/knex