If an email address in the "to:" list is in the style
"First Last <email@domain.tld>", ie: not just a bare
address like "email@domain.tld", and the same named
entry style exists in the "cc:" list, the current
logic will not remove the entry from the "cc:" list.

Add logic to better deduplicate the "cc:" list by also
matching the email address with angle brackets.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>