[mod_magnet] use type returned from lua_getfield()
[mod_magnet] use type returned from lua_getfield()

use type returned from lua_getfield() and lua_getglobal() in lua 5.3+
(remove extra call to lua_type())

lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4