Adjusting startup timeout for ambari-server web UI

[#1]

The ambari-server script used to wait a fixed amount of time before it gave up and thought the server wasn't going to start. On slower systems or test systems this limit was really easy to hit (50 seconds). Thanks to JIRA AMBARI-20220 this timeout has been parameterized. By adding the server.startup.web.timeout property (measured in seconds) to /etc/ambari-server/conf/ambari.properties you can change the timeout to something like this:

...

server.startup.web.timeout=120

...

so you don't get errors like this:

# ambari-server start

...

Waiting for server start............................................................

DB configs consistency check: no errors and warnings were found.

ERROR: Exiting with exit code 1.

REASON: Server not yet listening on http port 8080 after 50 seconds. Exiting.

Note: You need at least Ambari 2.5 for this functionality to be supported