Revert "audit: tweak cpan secure urls"

This reverts commit 7bbcf9ca.

Library/Homebrew/cmd/audit.rb

@@ -1167,7 +1167,7 @@ class ResourceAuditor
            %r{^http://(?:[^/]*\.)?archive\.org},
            %r{^http://(?:[^/]*\.)?freedesktop\.org}
         problem "Please use https:// for #{p}"
-      when %r{^http://search\.(mcpan|cpan)\.org/CPAN/(.*)}i
+      when %r{^http://search\.mcpan\.org/CPAN/(.*)}i
         problem "#{p} should be `https://cpan.metacpan.org/#{$1}`"
       when %r{^(http|ftp)://ftp\.gnome\.org/pub/gnome/(.*)}i
         problem "#{p} should be `https://download.gnome.org/#{$2}`"