default.mspec: remove useless flags

* spec/default.mspec: removed -I options for useless or non-
  existent paths from flags.  there is no library scripts and .ext
  directory in the source directory.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58949 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/default.mspec

@@ -18,8 +18,6 @@ class MSpecScript
   set :prefix, File.expand_path('rubyspec', File.dirname(__FILE__))
   set :flags, %W[
     -I#{srcdir}/lib
-    -I#{srcdir}
-    -I#{srcdir}/#{config['EXTOUT']}/common
     #{srcdir}/tool/runruby.rb --archdir=#{Dir.pwd} --extout=#{config['EXTOUT']}
     --
   ]