Change Details

``` Remove compatibility code not needed now when we're on Python 3. ``` Backport of core PR12993 https://github.com/bitcoin/bitcoin/pull/12993/files Depends on D3557

``` Remove compatibility code not needed now when we're on Python 3. ``` Backport of core PR12993 https://github.com/bitcoin/bitcoin/pull/12993/files Depends on D3556

``` Remove compatibility code not needed now when we're on Python 3. ``` Backport of core PR12993 https://github.com/bitcoin/bitcoin/pull/12993/files Depends on D35576