pk: Set synchronous pragma on all databases
pk: Set synchronous pragma on all databases

- "PRAGMA synchronous" turns out to set the pragma only on the main
database, not on attached databases.  Make sure to set the pragma on
attached databases as well, using undocumented syntax.  (The temp
database defaults to synchronous = OFF, and we don't change that.)

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr