Skip flaky grub_cmd_set_date test

Bug-Debian: https://bugs.debian.org/906470
Last-Update: 2018-10-28

Patch-Name: skip-grub_cmd_set_date.patch

tests/grub_cmd_set_date.in

 #! @BUILD_SHEBANG@
 set -e
 
+echo "Skipping flaky test."
+exit 77
+
 . "@builddir@/grub-core/modinfo.sh"
 
 case "${grub_modinfo_target_cpu}-${grub_modinfo_platform}" in