Represent plan_output_fh less verbosely.

Co-authored-by: Ross McFarland <ross@github.com>

octodns/manager.py

@@ -272,7 +272,7 @@ class Manager(object):
         self.log.info('sync: eligible_zones=%s, eligible_targets=%s, '
                       'dry_run=%s, force=%s, plan_output_fh=%s',
                       eligible_zones, eligible_targets, dry_run, force,
-                      plan_output_fh)
+                      getattr(plan_output_fh, 'name', plan_output_fh.__class__.__name__))
 
         zones = self.config['zones'].items()
         if eligible_zones: