fiddle/extconf.rb: supply 0
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46485 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
fiddle/extconf.rb: supply 0
with 3-digit. libffi 3.1 returns just 2-digit.
[ruby-core:62920] [Bug #9897]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46485 b2dd03c8-39d4-4d8f-98ff-823fe69b080e