[CMake] Boost_ADDITIONAL_VERSIONS works not correctly

[Rolf Eike Beer]

> find_package(Boost COMPONENTS ${GGMCONTROL_BOOST_COMPONENTS} REQUIRED)
> if(NOT Boost_FOUND)
>     # Try again with the other type of libs
>     set(Boost_USE_STATIC_LIBS NOT ${Boost_USE_STATIC_LIBS})
>     find_package(Boost COMPONENTS ${GGMCONTROL_BOOST_COMPONENTS} QUIET)
> endif()

This has nothing to do with your problem, but this is wrong. Since you put
in REQUIRED CMake will return with an error from the configuration stage.
So the if() clause doesn't really have any effect.

Eike