BuildSystem: Enable Lua 5.4.

Note to maintainers: Lua 5.4, Lua 5.3, and Lua 5.2 have not been tested
at runtime with pbx_lua. Until then, use the lowest available version
of Lua, if you enabled the module pbx_lua at all.

Change-Id: Ie5270448b11fcb4e2a53d899e4fe7fea793ce7e0

configure

@@ -29630,7 +29630,7 @@ fi
 
 
 
-for ver in 5.3 5.2 5.1; do
+for ver in 5.4 5.3 5.2 5.1; do
 
 if test "x${PBX_LUA}" != "x1" -a "${USE_LUA}" != "no"; then
    pbxlibdir=""