Entry version gets lost during topology change -> NPE

Replicated TX cache with WSC, A, B are in cluster, C is joining

0. The current CH already contains A and B as owners, C is joining (is not primary owner of anything yet). B is primary owner of K=V.
1. A sends PrepareCommand to B and C with put(K, V) (V is null on all nodes)
2. C receives PrepareCommand and responds with no versions (it is not primary owner)
3. topology changes on B - primary ownership of K is transfered to C
4. B receives PrepareCommand, responds without K's version (it is not primary)
5. B forwards the Prepare to C as it sees that the command has lower topology ID
6. C responds to B's prepare with version of K
7. K version is not added to B's response, B responds to A
8. A finds out that topology has changed, forwards prepare to C
9. C responds to C's prepare with version of K
10. A receives C's response, but the versions are not added to transaction
11. A sends out CommitCommand missing version of K
12. all nodes record K=V without version as usual ImmortalCacheEntry
13. the next time we try to increase version of K=V, we fail with NPE in SimpleClusteredVersionGenerator (actually when it tries to throw IllegalArgumentException because the null version is unexpected version class)