Problem with qan-api after upgrade to 1.4.0 from landing page.

1. Install PMM server and client 1.3.0
2. Add metrics to monitoring:

   sudo pmm-admin add mysql

3. Enable pmm-laboratory repository
4. Update PMM to 1.4 via button on landing page
5. Check docker logs
   Result:

   2017-10-19 20:47:07,775 INFO spawned: 'pmm-manage' with pid 1405
   2017-10-19 20:47:08,796 INFO success: qan-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
   2017-10-19 20:47:08,797 INFO success: pmm-manage entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
   2017-10-19 20:47:08,803 INFO spawned: 'nginx' with pid 1410
   2017-10-19 20:47:09,825 INFO success: nginx entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
   2017-10-19 20:47:09,838 INFO reaped unknown pid 1256
   2017-10-19 20:47:11,967 INFO exited: qan-api (exit status 1; not expected)
   2017-10-19 20:47:12,973 INFO spawned: 'qan-api' with pid 1423
   2017-10-19 20:47:13,977 INFO success: qan-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
   2017-10-19 20:47:18,001 INFO exited: qan-api (exit status 1; not expected)

In qan-api.log:

ERROR: logging before flag.Parse: I1019 20:53:36.915032    2050 logutil.go:31] log: API root dir /usr/share/percona-qan-api/src/github.com/percona/qan-api
ERROR: logging before flag.Parse: I1019 20:53:36.917156    2050 logutil.go:31] log: Error 1045: Access denied for user 'percona'@'localhost' (using password: YES)

Everything works OK with docker way upgrade