don't list IMAP Path under INBOX twice

if NAMESPACE is "INBOX.", listing INBOX recursively will already include
it.

REFMAIL: 1890363108.1020695.1428757117731.JavaMail.yahoo@mail.yahoo.com

src/drv_imap.c

@@ -2612,7 +2612,7 @@ imap_list_store( store_t *gctx, int flags,
 	imap_store_t *ctx = (imap_store_t *)gctx;
 	struct imap_cmd_refcounted_state *sts = imap_refcounted_new_state( cb, aux );
 
-	if (((flags & LIST_PATH) &&
+	if (((flags & LIST_PATH) && (!(flags & LIST_INBOX) || !is_inbox( ctx, ctx->prefix, -1 )) &&
 	     imap_exec( ctx, imap_refcounted_new_cmd( sts ), imap_refcounted_done_box,
 	                "LIST \"\" \"%\\s*\"", ctx->prefix ) < 0) ||
 	    ((flags & LIST_INBOX) && (!(flags & LIST_PATH) || *ctx->prefix) &&