Change url_code_map[] from an array of pointers to an array of arrays

Change url_code_map[] from an array of pointers to an array of arrays

It removes an unnecessary layer of indirection and on
my 64bit system reduces the size of the binary by 2k.

At least in theory it should be more cache-efficient as well
but given that this is not a hot code path I couldn't be
bothered to run micro benchmarks.