ilmbase 2.2.0-x upload to sid

[Mathieu Malaterre]

Hi there,

I am planning on uploading ilmbase 2.2.0-x to sid. The only rdepends is
openexr, so it should not impact anyone. This way I'll be able to upload
openexr 2.2.0-1 to experimental since it requires ilmbase >= 2.2.0

Thanks