Bug#1030842: fontforge: segfault during Open() of femkeklaver (inside pbuilder/lxc)

[Gioele Barabucci <gioele@svario.it>]

Stacktrace (with incomplete symbols):

```
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7974dd9 in ?? () from /lib/x86_64-linux-gnu/libc.so.6

#0  0x00007ffff7974dd9 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff7895425 in fputs () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff7b58a9a in ?? ()
   from /lib/x86_64-linux-gnu/libfontforge.so.4
#3  0x00007ffff7b58c49 in ?? ()
   from /lib/x86_64-linux-gnu/libfontforge.so.4
#4  0x00007ffff7b8555a in _SFReadTTF ()
   from /lib/x86_64-linux-gnu/libfontforge.so.4
#5  0x00007ffff7c66a7a in _ReadSplineFont ()
   from /lib/x86_64-linux-gnu/libfontforge.so.4
#6  0x00007ffff7c67a51 in LoadSplineFont ()
   from /lib/x86_64-linux-gnu/libfontforge.so.4
```