Catch SdBusError when calling the mapper

In certain cases, the mapper may return a not found error when polling
for BMC endpoints.  While this is an error, it should not crash
phosphor-software-manager.

Tested By: Booted the system without a bmc interface present, and
verified that software manager doesn't crash

Change-Id: I1199d6f94deb6cf5a795f8770d9dac202697f401
Signed-off-by: Ed Tanous <ed.tanous@intel.com>
1 file changed