Clean obsolete Qt5-related CMake settings.

cmake/GeoModelIOConfig.cmake.in

 # Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 
 # First off, import the upstream dependencies of the project.
-find_package( Qt5 COMPONENTS Core Sql )
 find_package( GeoModelCore @GeoModelCore_VERSION@ )
 
 # Now include the exported configuration of GeoModelIO.
@@ -15,7 +14,7 @@ set( GeoModelIO_VERSION "@PROJECT_VERSION@" )
 include( FindPackageHandleStandardArgs )
 find_package_handle_standard_args( GeoModelIO
    FOUND_VAR GeoModelIO_FOUND
-   REQUIRED_VARS SELF_DIR Qt5_FOUND GeoModelCore_FOUND
+   REQUIRED_VARS SELF_DIR GeoModelCore_FOUND
    VERSION_VAR GeoModelIO_VERSION )
 
 # Clean up.