disable compilation of test catch when tests turned off
disable compilation of test catch when tests turned off

a side effect is that this allows compilation under visstudio2013
where noexcept is not available.

ospray/OSPRay,ospray/OSPRay,wilsonCernWq/ospray,wilsonCernWq/ospray,ospray/OSPRay,wilsonCernWq/ospray,ospray/OSPRay