Does not build on FreeBSD

[probonopd]

Now that we are working on support for FreeBSD to use AppImages originally made for Linux, it would be nice to get the thumbnailer to run there, too.

Trying to compile this thumbnailer on FreeBSD leads to:

sed: 1: "configure": command c expects \ followed by text

Similar:
https://stackoverflow.com/questions/4247068/sed-command-with-i-option-failing-on-mac-but-works-on-linux

find . -type file -exec sed -i -e "s|sed -e|sed -i'' -e|g" {} \;

results in a failure with another symptom.

Blocked by:
AppImageCommunity/libappimage#149