Revert "python-paramiko: Add patch for ECDSA ..."

This reverts commit 58fdf342, because it
wasn't actually very fitting for nixpkgs in general, so let's wait for
the upcoming upstream release to address this.

Details can be found at:

https://github.com/NixOS/nixpkgs/commit/58fdf34#commitcomment-4231461



Thanks to @iElectric for the notice.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>