ConfigMgr: properly write configuration file if it contains non-ASCII chars

There has been a problem UTF-8 characters in the configuration file
since 2006 (!), as the length of the data to be written was mis-
calculated. We can omit the specification of the data length at all
when just passing a QByteArray object to QFile::write().

Fixes setup dialog appearing each start if one of the configured paths
in the setup dialog contains non-ASCII characters.

Closes #3348920, #3017409, #2812054.

src/core/config_mgr.cpp

@@ -1,10 +1,8 @@
-#ifndef SINGLE_SOURCE_COMPILE
-
 /*
  * config_mgr.cpp - implementation of class configManager
  *
- * Copyright (c) 2005-2008 Tobias Doerffel <tobydox/at/users.sourceforge.net>
- * 
+ * Copyright (c) 2005-2011 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
  * This program is free software; you can redistribute it and/or
@@ -24,7 +22,6 @@
  *
  */
 
-
 #include <QtXml/QDomElement>
 #include <QtCore/QDir>
 #include <QtCore/QFile>
@@ -454,10 +451,8 @@ void configManager::saveConfigFile()
 		return;
 	}
 
-	outfile.write( xml.toUtf8().constData(), xml.length() );
+	outfile.write( xml.toUtf8() );
 	outfile.close();
 }
 
 
-
-#endif