modify version check for ExtUtils::MakeMaker in Makefile.PL

Display the following message when executing 'perl Makefile.PL PREFIX=~/.local',

'Argument "6.55_02" isn't numeric in numeric ge (>=) at Makefile.PL line 6.',

cause $ExtUtils::MakeMaker::VERSION is not numeric.

So I think that you should use 'eval($ExtUtils::MakeMaker::VERSION)' to improve the message.

Thank you.