don't exceed 32-column index limit for temporary table in attributegroup API
don't exceed 32-column index limit for temporary table in attributegroup API

We index the temporary table for bulk update performance, but shouldn't
cause a runtime error if the user included a lot of metakey columns. Just
truncate the index and let Postgres generate a more expensive query if
necessary for this input...

informatics-isi-edu/ermrest,informatics-isi-edu/ermrest