bmc-state-manager: Fix error in GetUnit

obmc-standby.target was removed in meta-phosphor:
  https://gerrit.openbmc-project.xyz/c/openbmc/meta-phosphor/+/20665
This caused an error in a phosphor-bmc-state-manager's GetUnit call.
Moving over to multi-user.target instead fixes the error.

Resolves: https://github.com/openbmc/phosphor-state-manager/issues/6

Tested: Verified the error no longer pops up

Change-Id: I3f0546284091f63717882db5998b9faa34855d6f
Signed-off-by: Anthony Wilson <wilsonan@us.ibm.com>
1 file changed