Make test for policy 54 more accurate to avoid complaints.

Author: abh3

CMakeLists.txt

@@ -8,7 +8,7 @@ set( CMAKE_MODULE_PATH
  ${PROJECT_SOURCE_DIR}/src
  ${PROJECT_SOURCE_DIR}/cmake )
 
-if(CMAKE_VERSION VERSION_GREATER "3.0")
+if(NOT (CMAKE_VERSION VERSION_LESS "3.1"))
   cmake_policy(SET CMP0054 OLD)
 endif()