QDBusObjectPath: add ctor taking QString&&

The new constructor cannot be marked nothrow, because it calls
non-nothrow doCheck();

Change-Id: I4e5b33c58125091644573ed84e715c7fa946ae09
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbusextratypes.h

@@ -58,6 +58,9 @@ public:
     inline explicit QDBusObjectPath(const char *path);
     inline explicit QDBusObjectPath(QLatin1String path);
     inline explicit QDBusObjectPath(const QString &path);
+#ifdef Q_COMPILER_RVALUE_REFS
+    explicit QDBusObjectPath(QString &&p) : m_path(std::move(p)) { doCheck(); }
+#endif
 
     inline void setPath(const QString &path);