Fix escaping
Fix escaping

Without this the following is written to the image:

command="foreman start --procfile=Procfile \"\""
dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles,dokku-alt/progrium-buildstep-dockerfiles