Berkeley DB installer in contrib makes a call over the internet to https://gist.githubusercontent.com to fetch a 141 line patch.

The gist has multiple revisions

Expected behavior

One less call over the internet during the build process. One less website to depend on.

To reproduce

 ./contrib/install_db4.sh 

install_db4.sh is recommended by the doc/build-*.md for example https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md#berkeley-db

CC: @laanwj