CMake: Don't force OSX deployment target

Author: ilya-fedin

CMakeLists.txt

@@ -16,7 +16,6 @@ endif()
 set(not_packaged_build 0)
 if (NOT TG_OWT_PACKAGED_BUILD)
     set(not_packaged_build 1)
-    set(CMAKE_OSX_DEPLOYMENT_TARGET 10.13 CACHE STRING "Minimum OS X deployment version" FORCE)
 endif()
 
 option(BUILD_SHARED_LIBS "Builds shared libraries instead of static." OFF)