Status printer does not handle stderr

[friscoMad]

Expected Behavior

No log appear while status is printed in console

Current Behavior

Every now and then a single line appear in the screen.

Possible Solution

Handle properly the log levels of both handlers.

Steps to Reproduce (for bugs)

1. Start with --print-status workers
2. Wait until some warn is logged

Context

Your Environment

• Version used: Latest
• Environment name and version (e.g. Python 2.7): 2.7
• Operating System and version (desktop or mobile): Centos 7

I am not really sure if the issue is caused by the stderr handler but it seems the most logic cause.