CLEANUP: listener: remove unused conf->file and conf->line

These ones are already in bind_conf.
diff --git a/include/types/listener.h b/include/types/listener.h
index 0985329..2406148 100644
--- a/include/types/listener.h
+++ b/include/types/listener.h
@@ -152,8 +152,6 @@
 	/* warning: this struct is huge, keep it at the bottom */
 	struct sockaddr_storage addr;	/* the address we listen to */
 	struct {
-		const char *file;	/* file where the section appears */
-		int line;		/* line where the section appears */
 		struct eb32_node id;	/* place in the tree of used IDs */
 	} conf;				/* config information */
 };
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 8a7b29a..07b7347 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1455,8 +1455,6 @@
 			}
 			new = curproxy->listen;
 			while (new != last) {
-				new->conf.file = file;
-				new->conf.line = linenum;
 				new = new->next;
 				global.maxsock++;
 			}
@@ -1702,8 +1700,6 @@
 
 		new_listen = curproxy->listen;
 		while (new_listen != last_listen) {
-			new_listen->conf.file = file;
-			new_listen->conf.line = linenum;
 			new_listen->bind_conf = bind_conf;
 			new_listen = new_listen->next;
 			global.maxsock++;
@@ -2054,7 +2050,7 @@
 				if (node) {
 					l = container_of(node, struct listener, conf.id);
 					Alert("parsing [%s:%d]: custom id %d for socket '%s' already used at %s:%d.\n",
-					      file, linenum, l->luid, args[1], l->conf.file, l->conf.line);
+					      file, linenum, l->luid, args[1], l->bind_conf->file, l->bind_conf->line);
 					err_code |= ERR_ALERT | ERR_FATAL;
 					goto out;
 				}