main/iputils: Update to 20200821
Changes related to this release:
- Define BUILD_TFTPD=true, because tftpd has been disabled by default
- Removed openssl-dev build dependency because MD5 implementation was copied to iputils project.
- Update paths for ping, tftpd (moved to own directories).
- Drop patch from this release.
Signed-off-by: Petr Vorel petr.vorel@gmail.com