* Index the Builds table on drvPath to prevent a full table scan

Dependencies

• [2] O25D52TA initial support for mercurial
• [*] N22GPKYT * Put info about logs / build products in the DB.
• [*] 2I2ZX6JB * Make the "latest succeeded" query (used by the "latest" channel)

Change contents

• edit in src/sql/hydra.sql at line 529
  [5.804]

  [2.2946]
  + create index IndexBuildsOnDrvPath on Builds(drvPath);