iamp-send.c: remove unused struct imap_store_conf

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

imap-send.c

@@ -130,11 +130,6 @@ static struct imap_server_conf server = {
 	NULL,	/* auth_method */
 };
 
-struct imap_store_conf {
-	struct store_conf gen;
-	struct imap_server_conf *server;
-};
-
 #define NIL	(void *)0x1
 #define LIST	(void *)0x2