Simply adjust the NeL version in code/CMakeLists.txt.
code/CMakeLists.txt
SET(NL_VERSION_MAJOR 1) SET(NL_VERSION_MINOR 0) SET(NL_VERSION_PATCH 0)
Reference: https://github.com/ryzom/ryzomcore/commit/0017a5fb26d090a1b837a1aff18f0d8c59174687