test/jsonTesterLua.c: Restore explicit encoding set in lua_empty_string [ci skip]
test/jsonTesterLua.c: Restore explicit encoding set in lua_empty_string [ci skip]

jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF