It looks like you missed part of the fix as there is also a breaks on fgfs-scenery-base.
Package: flightgear-data-base Architecture: all Depends: tzdata, fonts-liberation, ${misc:Depends} Replaces: fgfs-base (<< 2.10.0), fgfs-scenery-base (<< 2.10.0) Breaks: flightgear (<< 2.10.0~), fgfs-base (<< 2.10.0~), fgfs-scenery-base (<< 2.10.0~), fgfs-aircraft-base (<< 2.10.0~)
It looks like you missed part of the fix as there is also a breaks on fgfs-scenery-base.
Package: flightgear- data-base
Architecture: all
Depends: tzdata, fonts-liberation, ${misc:Depends}
Replaces: fgfs-base (<< 2.10.0), fgfs-scenery-base (<< 2.10.0)
Breaks: flightgear (<< 2.10.0~),
fgfs-base (<< 2.10.0~), fgfs-scenery-base (<< 2.10.0~),
fgfs-aircraft-base (<< 2.10.0~)