doc/radosgw: Fix section header level in config-ref.rst

The section named "QoS Settings" looks like it should not be a child of
the section "SSE-S3 Settings". Move it to be a sibling to it, on the
same level instead.

Signed-off-by: Ville Ojamo <[email protected]>

Author: bluikko

doc/radosgw/config-ref.rst

@@ -260,7 +260,7 @@ SSE-S3 Settings
 
 
 QoS settings
-------------
+============
 
 .. versionadded:: Nautilus