QLoggingRegistry: allow Rules section to be lower case

In http://blog.qt.io/blog/2014/03/11/qt-weekly-1-categorized-logging/
the Rules section is given as:
[rules]
...

While in reality only Rules was accepted. Ignore casing instead.

Change-Id: Ibf0da6b6df857988d508ba9ec354cbce0b2c56d6
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

src/corelib/io/qloggingregistry.cpp

@@ -208,7 +208,7 @@ void QLoggingSettingsParser::setContent(QTextStream &stream)
             continue;
         }
 
-        if (_section == QLatin1String("Rules")) {
+        if (_section.toLower() == QLatin1String("rules")) {
             int equalPos = line.indexOf(QLatin1Char('='));
             if (equalPos != -1) {
                 if (line.lastIndexOf(QLatin1Char('=')) == equalPos) {