Fixed bug #79678 Build fails due to undeclared ZIP_RDONLY

Author: remicollet

ext/zip/php_zip.c

@@ -1456,7 +1456,11 @@ PHP_METHOD(ZipArchive, open)
 	   "Do not accept empty files as valid zip archives any longer" */
 
 	/* open for write without option to empty the archive */
+#ifdef ZIP_RDONLY
 	if ((flags & (ZIP_TRUNCATE | ZIP_RDONLY)) == 0) {
+#else
+	if ((flags & ZIP_TRUNCATE) == 0) {
+#endif
 		zend_stat_t st;
 
 		/* exists and is empty */