Avoid CMake policy CMP0072 warning
Avoid CMake policy CMP0072 warning

Prefer libGL over libOpenGl for better compatibility with SWR.

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