Please replace hard coded library path in CMakeLists.txt

[strahlc]

please use cmake variables instead of hard coded paths according to this patch (patch doesn't apply on master directly)

https://github.com/openembedded/meta-openembedded/blob/master/meta-oe/recipes-devtools/jsonrpc/jsonrpc/0001-cmake-replace-hardcoded-lib-CMAKE_LIBRARY_PATH-with-.patch