main/lua-xml: add subpkg lua5.3-*, remove subpkg lua5.1-*

This version of LuaXML does not workd, and never worked, on Lua 5.1
or LuaJIT.

main/lua-xml/APKBUILD

 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
-_luaversions="5.1 5.2"
+_luaversions="5.2 5.3"
 pkgname=lua-xml
 _name=luaxml
 pkgver=130610