NetworkIdentity.DeserializeServer sets all [SyncVar] dirty bits instead of the synced ones

that's because not all OnSerialize calls may have SyncVars.

however, OnDeserialize calls the syncvar setter for the ones which were modified.
-> simply set the dirty bit there.

... and then remove the SetDirty() call? but what about other types?
  maybe only call SetDirty() if syncVarDirtyBits == 0 after deseriaalize