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

This reverts commit 58fdf3429640d2447501fff15a7da9103fb8653a, 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>