CMake Error: The target name "package_source" is reserved when CPack source packaging is enabled.
In r24, running cmake under Linux:
```
-- BornAgain build log written to '/G/sw/ba/build/bornagain_build.log'
-- CMake done
CMake Error at cmake/BornAgain/Pack.cmake:32 (add_custom_target):
The target name "package_source" is reserved when CPack source packaging is
enabled.
Call Stack (most recent call first):
CMakeLists.txt:296 (include)
-- Configuring incomplete, errors occurred!
```
issue