Guard the flag used for deferred session configure.

src/base/bittorrent/session.h

@@ -41,6 +41,7 @@
 #endif
 #include <QNetworkConfigurationManager>
 #include <QPointer>
+#include <QReadWriteLock>
 #include <QStringList>
 #include <QVector>
 #include <QWaitCondition>
@@ -604,6 +605,8 @@ namespace BitTorrent
 
         QNetworkConfigurationManager m_networkManager;
 
+        mutable QReadWriteLock m_lock;
+
         static Session *m_instance;
     };
 }