add des cluster when perform 'allter system add backend'#134

Merged

chenhao7253886 merged 2 commits intoapache:masterfrom chenhao7253886:master

Nov 3, 2017

+112-43

Commits on Nov 3, 2017

CreateTableStmt and AlterTableStmt cluster name is null
chenhao16
committed
add des cluster when perform 'allter system add backend'
chenhao16
committed