In order to avoid http 503 errors and taking a look
at php fpm logs , its has been increased the
start_servers, min_spare_servers and max_spare_servers
values to avoid erros like WARNING: [pool www] seems busy
(you may need to increase pm.start_servers, or
pm.min/max_spare_servers).
Change-Id: I5d47625ac4702c1b6704c66967d76fac2a895907