extract_v2: handle "untrusted package" as normal error

The "untrusted" error is higher priority than malformed package.
But given that we expect valid .apk or index as argument, the
untrusted error is likely more accurate than having malformed
package.

src/extract_v2.c

@@ -356,7 +356,7 @@ int apk_extract_v2(struct apk_extract_ctx *ectx, struct apk_istream *is)
 		apk_istream_gunzip_mpart(is, apk_sign_ctx_mpart_cb, &sctx),
 		apk_extract_v2_entry, ectx, apk_ctx_get_id_cache(ac));
 	if (r == -ECANCELED) r = 0;
-	if ((r == 0 || r == -APKE_SIGNATURE_UNTRUSTED || r == -APKE_EOF) && !ectx->is_package && !ectx->is_index)
+	if ((r == 0 || r == -APKE_EOF) && !ectx->is_package && !ectx->is_index)
 		r = ectx->ops->v2index ? -APKE_V2NDX_FORMAT : -APKE_V2PKG_FORMAT;
 	if (ectx->generate_identity) *ectx->identity = sctx.identity;
 	apk_sign_ctx_free(&sctx);