Drop the errorMsg column in the Jobs table

We're not using it anywhere.

src/script/hydra-evaluator

@@ -166,16 +166,6 @@ sub checkJobsetWrapped {
             checkBuild($db, $jobset, $inputInfo, $nixExprInput, $job, \%buildMap, $prevEval, $jobOutPathMap, $plugins);
         }
 
-        # Update the last checked times and error messages for each
-        # job.
-        my %failedJobNames;
-        push @{$failedJobNames{$_->{location}}}, $_->{msg} foreach @{$jobs->{error}};
-
-        $jobset->update({lastcheckedtime => time});
-
-        $_->update({ errormsg => $failedJobNames{$_->name} ? join '\n', @{$failedJobNames{$_->name}} : undef })
-            foreach $jobset->jobs->all;
-
         # Have any builds been added or removed since last time?
         my $jobsetChanged =
             (scalar(grep { $_->{new} } values(%buildMap)) > 0)
@@ -249,6 +239,8 @@ sub checkJobsetWrapped {
 
         # If this is a one-shot jobset, disable it now.
         $jobset->update({ enabled => 0 }) if $jobset->enabled == 2;
+
+        $jobset->update({ lastcheckedtime => time });
     });
 
     # Store the error messages for jobs that failed to evaluate.