Change the order of python suffixes

This puts the suffix for boost-python to be the one suggested by the
cmake docs https://cmake.org/cmake/help/v3.14/module/FindBoost.html

buildconfig/CMake/FindBoostPython.cmake

@@ -10,7 +10,7 @@ else ()
   # Try a known set of suffixes plus a user-defined set
   # Define a cache variable to supply additional suffxies. These are tried first
   set ( BOOST_PYTHON_ADDITIONAL_SUFFIXES "" CACHE STRING "Additional suffixes to try when searching for the boost python3 library. These are prepended to the default list" )
-  set ( _suffixes "${BOOST_PYTHON_ADDITIONAL_SUFFIXES};${Python_VERSION_MAJOR};-py${Python_VERSION_MAJOR}${Python_VERSION_MINOR};${Python_VERSION_MAJOR}${Python_VERSION_MINOR}")
+  set ( _suffixes "${BOOST_PYTHON_ADDITIONAL_SUFFIXES};${Python_VERSION_MAJOR}${Python_VERSION_MINOR};${Python_VERSION_MAJOR};-py${Python_VERSION_MAJOR}${Python_VERSION_MINOR}")
   foreach ( _suffix ${_suffixes})
     find_package ( Boost ${BOOST_VERSION_REQUIRED} COMPONENTS python${_suffix} )
     if ( Boost_FOUND )