CMake packaging fix. (#1674)

* CMake packaging fix.

Add find_dependency for the new dependency libdeflate, and remove the REQUIRED flag. find_dependency will pickup the correct flag from the calling find_package call.

Signed-off-by: Peter Steneteg <peter@steneteg.se>

* find_dependency only if libdeflate_FOUND

Signed-off-by: Cary Phillips <cary@ilm.com>

* Need to expand the libdeflate_FOUND variable at configure_file time

Signed-off-by: Peter Steneteg <peter@steneteg.se>

---------

Signed-off-by: Peter Steneteg <peter@steneteg.se>
Signed-off-by: Cary Phillips <cary@ilm.com>
Co-authored-by: Cary Phillips <cary@ilm.com>

cmake/OpenEXRConfig.cmake.in

@@ -8,11 +8,15 @@ include(CMakeFindDependencyMacro)
 set(openexr_needthreads @OPENEXR_ENABLE_THREADING@)
 if (openexr_needthreads)
   set(THREADS_PREFER_PTHREAD_FLAG ON)
-  find_dependency(Threads REQUIRED)
+  find_dependency(Threads)
 endif()
 unset(openexr_needthreads)
 
-find_dependency(Imath REQUIRED)
+find_dependency(Imath)
+
+if (@libdeflate_FOUND@)
+  find_dependency(libdeflate)
+endif()
 
 include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
 check_required_components("@PROJECT_NAME@")