fix the non-Win32 build breakage introduced in ce9582af

On Unix, EU::MM was falling back to EU::MM::version::vpp, which
was removed above.

Make the real version.pm available instead.

write_buildcustomize.pl

@@ -38,6 +38,7 @@ my @toolchain = qw(cpan/AutoLoader/lib
                    ext/File-Find/lib
                    cpan/Text-Tabs/lib
 		   dist/constant/lib
+		   cpan/version/lib
 		   );
 
 # Text-ParseWords used only in ExtUtils::Liblist::Kid::_win32_ext()
@@ -49,7 +50,6 @@ push @toolchain, qw(
 	cpan/Getopt-Long/lib
 	cpan/parent/lib
 	cpan/ExtUtils-Constant/lib
-	cpan/version/lib
 ) if $^O eq 'MSWin32';
 push @toolchain, 'ext/VMS-Filespec/lib' if $^O eq 'VMS';