Update json.c
Update json.c

use array returned by marpa_r_terminals_expected() rather than its index
pczarn/kollos,jeffreykegler/kollos,jeffreykegler/libmarpa,pczarn/kollos,jeffreykegler/kollos,pczarn/kollos,jeffreykegler/kollos,jeffreykegler/libmarpa,jeffreykegler/kollos,jeffreykegler/libmarpa,pczarn/kollos,jeffreykegler/libmarpa,jeffreykegler/kollos,jeffreykegler/libmarpa,pczarn/kollos