ovirt_engine_setup: add update possibility

[petr-balogh]

For update there is no need stop ovirt-engine service, so in this case when you pass ovirt_engine_update: True, setup packages will be updated and engine-setup will be ran.

Change-Id: I801c64924359ce8b114374ab54f4c3145d5dfa9a

[lukas-bednar]

It looks like you have a problem with remote DB.

          --== DATABASE CONFIGURATION ==--

          Found the following problems in PostgreSQL configuration for the Engine database:
           autovacuum_vacuum_scale_factor required to be at most 0.01
           autovacuum_analyze_scale_factor required to be at most 0.075
           autovacuum_max_workers required to be at least 6
           maintenance_work_mem required to be at least 65536
           max_connections required to be at least 150
           Engine requires lc_messages to be 'en_US.UTF-8'. 
          Please set:
           autovacuum_vacuum_scale_factor = 0.01
           autovacuum_analyze_scale_factor = 0.075
           autovacuum_max_workers = 6
           maintenance_work_mem = 65536
           max_connections = 150
           lc_messages = 'en_US.UTF-8'
          in postgresql.conf on '172.17.0.2'. Its location is usually /var/lib/pgsql/data , or somewhere under /etc/postgresql* .
[ ERROR ] Failed to execute stage 'Environment customization': Please fix PostgreSQL configuration and retry.
[ INFO  ] Stage: Clean up
          Log file is located at /var/log/ovirt-engine/setup/ovirt-engine-setup-20170522162718-4vgh6u.log
[ INFO  ] Generating answer file '/var/lib/ovirt-engine/setup/answers/20170522162725-setup.conf'
[ INFO  ] Stage: Pre-termination
[ INFO  ] Stage: Termination

It might be also problem with remote-db role ... or bug in oVirt