Fix a corner case where automatic APLOGNO number generation generates invalid code...

Fix a corner case where automatic APLOGNO number generation generates invalid code. (see r1864733 fixed in r1864736, thx Eric)

Not sure why this ,? is there, but it looks uneeded to me.
There is maybe a link with the patterns used in 'find-messages.cocci'. They seem to add some extra , after the empty APLOGNO() it generates.
I will investigate further and fix 'find-messages.cocci' accordingly if needed.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1864771 13f79535-47bb-0310-9956-ffa450edef68