Bug#1112343: f3d: FTBFS with assimp-6.x

[IOhannes m zmoelnig]

Source: f3d
Version: 3.1.0+dfsg-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)

Dear Maintainer,

I'm currently preparing an upload of assimp-6.x to the Debian archives.

during a rebuild of all dependencies, I noticed that 'f3d' no longer compiles
with the new assimp, because it uses a versioned dependency in
`plugins/assimp/CMakeLists.txt`:
```cmake
find_package(assimp 5.4.0 REQUIRED)
```

removing the version number fixes the build issue.

please note, that f3d_3.2.0 (released about 2 months ago) already contains a fix
for this issue.


fmasre
IOhannes