Add trace when unknown user error

Have seen this internalError a few times. A trace would help debug why
User Manager is returning an error.

In line with
https://github.com/openbmc/bmcweb/blob/master/DEVELOPING.md#logging-levels.

IBM has bmcweb-logging=error enabled.

Tested: None. Visual only.

Change-Id: I16f56c3170fb92dcfb52e57c9a420cefabc4c763
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/redfish-core/lib/account_service.hpp b/redfish-core/lib/account_service.hpp
index dc21ff9..70a1506 100644
--- a/redfish-core/lib/account_service.hpp
+++ b/redfish-core/lib/account_service.hpp
@@ -312,6 +312,7 @@
     }
     else
     {
+        BMCWEB_LOG_ERROR("DBUS response error {}", errorMessage);
         messages::internalError(asyncResp->res);
     }
 }