Fix some raft backend node bugs

[Linary]

Change-Id: I22dc5111bf0676f60c8985a233aa746d1bffbb51

[codecov]

Codecov Report

Merging #1133 into master will decrease coverage by 0.58%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master    #1133      +/-   ##
============================================
- Coverage     65.85%   65.27%   -0.59%     
+ Complexity     5653     5602      -51     
============================================
  Files           354      354              
  Lines         28840    28851      +11     
  Branches       4064     4065       +1     
============================================
- Hits          18994    18832     -162     
- Misses         7966     8150     +184     
+ Partials       1880     1869      -11     

Impacted Files	Coverage Δ	Complexity Δ
...m/baidu/hugegraph/backend/store/raft/RaftNode.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...baidu/hugegraph/backend/store/raft/RaftResult.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...gegraph/backend/store/rocksdb/RocksDBFeatures.java	10.00% <0.00%> (-75.00%)	2.00% <0.00%> (-15.00%)
.../hugegraph/backend/store/rocksdb/RocksDBTable.java	16.15% <0.00%> (-56.16%)	10.00% <0.00%> (-27.00%)
...om/baidu/hugegraph/backend/store/BackendEntry.java	31.42% <0.00%> (-40.00%)	1.00% <0.00%> (ø%)
...hugegraph/backend/store/rocksdb/RocksDBTables.java	60.68% <0.00%> (-6.84%)	0.00% <0.00%> (ø%)
...raph/backend/store/rocksdb/RocksDBStdSessions.java	62.34% <0.00%> (-5.97%)	34.00% <0.00%> (-1.00%)
...om/baidu/hugegraph/backend/store/BackendTable.java	20.80% <0.00%> (-4.03%)	11.00% <0.00%> (ø%)
.../hugegraph/backend/store/rocksdb/RocksDBStore.java	61.55% <0.00%> (-3.63%)	56.00% <0.00%> (-4.00%)
...va/com/baidu/hugegraph/backend/cache/RamCache.java	71.83% <0.00%> (-0.58%)	27.00% <0.00%> (-1.00%)
... and 2 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 32adab5...4980fa5. Read the comment docs.