Fix External Index Creation

[arthurt]

Fixes regression introduced by 9b9301f

Currently

CREATE INDEX foo USING driver table (column)

creates a table scan if driver is not "", "btree" or "hash".

The regression is caused by the change:

-	outScope.node = plan.NewCreateIndex(
+	createIndex := plan.NewCreateIndex(
		ddl.IndexSpec.ToName.String(),
		table,
		cols,
		ddl.IndexSpec.Using.Lowered(),
		config,
	)
+	createIndex.Catalog = b.cat
	return

[fulghum]

Looks great! Thank you for helping us catch this one! 🙏

[fulghum]

Thank you for the contribution @arthurt! Sorry it took us so long to get to this one. Code change looks good to me and all the tests have passed now, so I'll go ahead and merge this one in.

Very good catch here on finding that missing call to set the outScope.node! Thank you for contributing this fix!! 🙏