[server] RootDir should be not NoLock but Mutex
[server] RootDir should be not NoLock but Mutex

Configuration is loaded as a result of concurrent operations, so it
should be protected

Signed-off-by: Denis Zalevskiy <43c40921ef02e9bb53daac07eb9ed16452640d88@jolla.com>

android-808/statefs,android-808/statefs,android-808/statefs,android-808/statefs