qubes/core2migration: make pylint happy
qubes/core2migration: make pylint happy

It doesn't see the class that is just being defined. But since it is in
lambda, that's ok.

woju/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,marmarek/qubes-core-admin