Fix docs/makedocs.pl to include email_in.pl in the API index (checkin fix for bug 350921)

docs/lib/Pod/Simple/HTMLBatch/Bugzilla.pm

@@ -31,7 +31,7 @@ BEGIN { *esc = \&Pod::Simple::HTML::esc }
 # Note that if you leave out a category here, it will not be indexed
 # in the contents file, even though its HTML POD will still exist.
 use constant FILE_TRANSLATION => {
-    Files      => ['importxml', 'contrib', 'checksetup'],
+    Files      => ['importxml', 'contrib', 'checksetup', 'email_in'],
     Modules    => ['bugzilla'],
     Extensions => ['extensions'],
 };