git-contacts: also recognise "Reported-by:"

It's nice to cc someone that reported a bug, in order to let them
know that a fix is being considered, and possibly even get their
help in reviewing/testing the patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/contacts/git-contacts

@@ -11,7 +11,7 @@ use IPC::Open2;
 
 my $since = '5-years-ago';
 my $min_percent = 10;
-my $labels_rx = qr/Signed-off-by|Reviewed-by|Acked-by|Cc/i;
+my $labels_rx = qr/Signed-off-by|Reviewed-by|Acked-by|Cc|Reported-by/i;
 my %seen;
 
 sub format_contact {