Fixed port number references

Fixed old Bitcoin port references by running:

grep -rl 18333 . | xargs sed -i "s/18333/20888/g"
grep -rl 18332 . | xargs sed -i "s/18332/20889/g"
grep -rl 8333 . | xargs sed -i "s/8333/10888/g"
grep -rl 8332 . | xargs sed -i "s/8332/10889/g"

# we don't want to change these files
git checkout src/test/data/sighash.json
git checkout src/test/data/tx_valid.json