package/rdesktop: security bump to version 1.8.6

package/rdesktop: security bump to version 1.8.6

- Fix CVE-2019-15682: RDesktop version 1.8.4 contains multiple
  out-of-bound access read vulnerabilities in its code, which results in
  a denial of service (DoS) condition. This attack appear to be
  exploitable via network connectivity. These issues have been fixed in
  version 1.8.5
- Update indentation of hash file (two spaces)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>