Does not run on Ubuntu xenial

[probonopd]

Hi, thanks for making an AppImage. However, it does not run on xenial since it likely was built on a too new system:

kflash_gui: relocation error: /run/firejail/appimage/.appimage-9355/usr/lib/libc.so.6: symbol _dl_exception_create, version GLIBC_PRIVATE not defined in file ld-linux-x86-64.so.2 with link time reference

Reference:
AppImage/appimage.github.io#2153

[AIWintermuteAI]

Confirmed. having same issue on Bionic(18.04) @Zepan

[Neutree]

This is just an attempt to appimage, it has not been fully packaged yet