[dovecot/core] ba4626: cassandra: Added metrics=path connect setting.

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: ba4626cd5be3d225a7a89aa338d92b8fb411fd1c
      https://github.com/dovecot/core/commit/ba4626cd5be3d225a7a89aa338d92b8fb411fd1c
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2016-05-25 (Wed, 25 May 2016)

  Changed paths:
    M src/lib-sql/driver-cassandra.c

  Log Message:
  -----------
  cassandra: Added metrics=path connect setting.

Cassandra's metrics are written to the path in JSON format. It can be a file
or a FIFO. The path supports expanding the standard global %variables, such
as %{pid}