debian: Fix changelog to use 4.4.1 release with snapshot in the version ...

Both 4.4.0 and 4.4.1 tagged releases have -snapshot in debian/changelog resulting in debian package names which should be 4.4.0 or 4.4.1 and not 4.4.0-snapshot or 4.4.1-snapshot. This is not the case in case of 4.3.1/4.3.0 and past releases. Since 4.4.1 has already been tagged, we can keep it this way. Sending this pull request just in case there is time to fix it?

Regards.