auto_schema: Avoid reusing sql variable in replica for loop

It makes it just prepend 'set session sql_log_bin=0; ' every time
and has the schema change that supposed to be ran with replication
runs without it because it was reusing sql variable from previous host
that was replica

Bug: T288235
Change-Id: I8d09dd670fbc487a3c84188f3ee8300e2fece2ad
1 file changed