Finally recent Gammu version (1.06.00) has been migrated to testing. It took so long as it needed manual hint because of both python-gammu/gammu breakage loops. Unfortunately there is no other way to resolve unstable Gammu ABI than using so strict dependencies.
Now I finally undestand why Gnokii is using that complex way for passing parameters. It is painful to use it, but it keeps ABI stable enough. We need to find better solution for this.