[close #540] rawkv: fix scan return empty set while exist empty key (#541)#548

marsishandsome merged 2 commits intotikv:release-3.1tikv/client-java:release-3.1from

iosmanthus:fix-scan-empty-key-for-3.1iosmanthus/client-java:fix-scan-empty-key-for-3.1Copy head branch name to clipboard