This resolves an issue when using both constraints with index
tablespaces AND constraints that have no indexes on a single hypertable.
chunk_constraint_add_table_constraint() was attempting to add
`USING INDEX TABLESPACE` to all constraints when a given hypertable had
any constraint configured to use a tablespace, resulting in a SYNTAX
error and blocking the creation of new chunks.
The solution here is to limit index tablespace lookups to only the
constraint types which use indexes: primary key and unique so that only
those constraits will have `USING INDEX TABLESPACE` prepended when
necessary.
1bccedf3f8