fix UInt8 type

[lmiq]

I was getting this error while reading some trajectories:

ERROR: MethodError: no method matching chfl_trajectory_with_format(::Ptr{UInt8}, ::Int8, ::Ptr{UInt8})

Closest candidates are:
  chfl_trajectory_with_format(::Ptr{UInt8}, ::UInt8, ::Ptr{UInt8})
   @ Chemfiles ~/.julia/packages/Chemfiles/Wzcgy/src/generated/cdef.jl:608

and this change seems to be the fix.

[lmiq]

Note: I´m getting this error running Julia on a linux emulation inside an android device. The error only manifests on this platform for me.

[Luthaf]

I guess this is an issue with char being defined as either signed or unsigned on different platforms. A better fix might actually be to use Cchar, which seems to handle this for us.

[lmiq]

thanks for the feedback. Changed it now, and tested in on both platforms (Linux emulated on ARM and x86) which I have access. Seems to work fine on both.

[Luthaf]

I might need to update the CI for this repository it is still using some old setup. I'll cherry-pick your commit on top after that.

[lmiq]

Don't worry if just changing the line is easier that merging the PR. I really don't mind. Thanks for your support.

[Luthaf]

PR is replaced by #80

[Luthaf]

The fix is now released in version 0.10.42!