Fixes CVE-2017-{2834,2835,2836,2837,2838,2839}. Reported by Leo Famulari in <https://bugs.gnu.org/27939>. * gnu/packages/rdesktop.scm (freerdp): Update to 2.0.0-rc0. [source]: Use tarball release. Adjust file-name. [arguments]: Remove #:phases.