Used the source column definition to fetch and convert insert values

When processing binlog insert statements, we want to use `sharedColumns`
to decide which values to fetch and convert from the insert DML event.

We only want to  `mappedShareColumns` to define the column names in the
`replace into ...` statement.

go/sql/builder.go

@@ -344,7 +344,7 @@ func BuildDMLInsertQuery(databaseName, tableName string, tableColumns, sharedCol
 	databaseName = EscapeName(databaseName)
 	tableName = EscapeName(tableName)
 
-	for _, column := range mappedSharedColumns.Columns() {
+	for _, column := range sharedColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
 		arg := column.convertArg(args[tableOrdinal])
 		sharedArgs = append(sharedArgs, arg)