[exim] header_sender test and group addresses

I thought I'd turn on the header_sender test, so I've been running it in
logging mode for a while. today I noticed these headers would be
rejected:

From: "TICKET INTERNETT          (AGENTID01138828)" <emailserver@???>
Reply-To: "Please do not respond":;

I want to be 100% sure before rejecting e-mail from Amadeus :-), and
according to my reading of RFC 2822, a group address is perfectly valid
in Reply-To:

reply-to        =       "Reply-To:" address-list CRLF
address-list    =       (address *("," address)) / obs-addr-list
address         =       mailbox / group
group           =       display-name ":" [mailbox-list / CFWS] ";"
                        [CFWS]

this occured with Exim 4.43, but I don't think this behaviour has been
changed in newer versions. looks like only a small patch is needed to
do this right, since there is a nice Boolean parse_allow_group already.

any input is welcome.
--
Kjetil T.