Log Message:
databases/pgbouncer: Update to 1.9.0.

Features

- RECONNECT command
- WAIT_CLOSE command
- Fast close - Disconnect a server in session pool mode immediately
  if it is in "close_needed" (reconnect) mode.
- Add close_needed column to SHOW SERVERS

Fixes

- Avoid double-free in parse_filename
- Avoid NULL pointer deref in parse_line

Cleanups

- Port mkauth.py to Python 3
- Improve signals documentation
- Improve quick start documentation
- Document SET command
- Correct list of required software
- Fix -Wimplicit-fallthrough warnings
- Add missing documentation for various SHOW fields
- Document reconnect behavior on reload and DNS change
- Document that KILL requires RESUME afterwards
- Clarify documentation of server_lifetime
- Typos and capitalization fixes in messages and docs
- Fix psql invocation in tests
- Various other test setup improvements