net/mwan3: remove check_quality option from default config

The normal situation should be to use ping without quality_check.
If quality_check option is not set in the default option then ping
quality_check is not performed during tracking. This is and should
be the default situation.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/mwan3/files/etc/config/mwan3

@@ -5,7 +5,6 @@ config globals 'globals'
 
 config interface 'wan'
 	option enabled '1'
-	option check_quality '1'
 	list track_ip '8.8.4.4'
 	list track_ip '8.8.8.8'
 	list track_ip '208.67.222.222'