Remove error message when the default_user.csv doesn't exist.

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/parkinglot@680 e5f2f494-b856-4b98-b285-d166d9295462

src/bin/bindctl/bindcmd.py

@@ -108,6 +108,8 @@ class BindCmdInterpreter(Cmd):
                     print(data + ' login as ' + row[0] )
                     bsuccess = True
                     break
+        except IOError as e:
+            pass
         except Exception as e:
             print(e)
         finally: