Configure fails with newer CMake

The configure step fails with the following error:

CMake Error at cmake/os/Linux.cmake:29 (STRING):
STRING sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
CMakeLists.txt:101 (INCLUDE)

CMake Error at cmake/os/Linux.cmake:29 (STRING):
STRING sub-command REPLACE requires at least four arguments.
Call Stack (most recent call first):
CMakeLists.txt:101 (INCLUDE)

The attached patch seems to fix the problem.