send-email: only allow one address per body tag

send-email: only allow one address per body tag

Adding comments after a tag in the body is a common practise (e.g. in
the Linux kernel) and git-send-email has been supporting this for years
by removing any trailing cruft after the address.

After some recent changes, any trailing comment is now instead appended
to the recipient name (with some random white space inserted) resulting
in undesirable noise in the headers, for example:

CC: "# 3 . 3 . x : 1b9508f : sched : Rate-limit newidle" <stable@vger.kernel.org>
Revert to the earlier behaviour of discarding anything after the (first)
address in a tag while parsing the body.

Note that multiple addresses after are still allowed after a command
line switch (and in a CC header field).

Also note that --suppress-cc=self was never honoured when using multiple
addresses in a tag.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>