Update xmake.lua

packages/l/libelf/xmake.lua

@@ -3,8 +3,7 @@ package("libelf")
     set_homepage("https://web.archive.org/web/20181111033959/www.mr511.de/software/english.html")
     set_description("ELF object file access library")
 
-    set_urls("https://dl.bintray.com/homebrew/mirror/libelf-$(version).tar.gz",
-             "https://github.com/xmake-mirror/libelf/releases/download/$(version)/libelf-$(version).tar.gz",
+    set_urls("https://github.com/xmake-mirror/libelf/releases/download/$(version)/libelf-$(version).tar.gz",
              "https://github.com/xmake-mirror/libelf.git")
     add_versions("0.8.13", "591a9b4ec81c1f2042a97aa60564e0cb79d041c52faa7416acb38bc95bd2c76d")