libubootenv: bump git srcrev
This includes the following changes:
9294981 handle protected mmcblk_boot_ devices
ac6d18a add missing includes
8106b65 add .editorconfig file
3286c57 CMakeLists: fix build with old compilers
4d05047 Merge pull request #3 from lamby/reproducible-build
d63e76f Make the build reproducible
Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>