check compiler version fatal -> warning

Author: igorkorsukov

buildscripts/cmake/CheckCompilerVersion.cmake

@@ -3,7 +3,7 @@
 function(check_compile_version name min_version hint_message)
     if (CMAKE_CXX_COMPILER_ID STREQUAL ${name})
         if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${min_version})
-            message(FATAL_ERROR
+            message(WARNING
                 "${CMAKE_CXX_COMPILER_ID} ${CMAKE_CXX_COMPILER_VERSION} is too old; "
                 "requires ${min_version} or newer. ${hint_message}")
         endif()