[SPARK-4421] Wrong link in spark-standalone.html

[tsudukim]

Modified the link of building Spark. (backport version of #3279.)

[AmplabJenkins]

Can one of the admins verify this patch?

[tsudukim]

I sent 2 PRs about SPARK-4421 because the page name are different between Spark 1.2 and Spark 1.1.
This is for Spark 1.1.

[srowen]

@tsudukim I think the practice is always to open a PR for master, not branches. The patch will be back-ported as appropriate. Could you change your PRs into one for master?

[tsudukim]

Thank you @srowen for following this ticket.
I know PR should be for master generally, and I already sent one for master (#3279).
But the details of modification for master and for branch-1.1 are different because the filename in master was changed from branch-1.1, so i thought branch-1.1 requires another PR and sent this (#3280).
If you don't need this PR, I will just close it.

[srowen]

That makes sense. I don't know if it is better to leave this or let the merger apply this change when it is applied to 1.1. It may not be worth it since docs are made from the latest release. Let them decide.

[JoshRosen]

LGTM; I'm going to merge this into branch-1.1. GitHub won't automatically close PRs via commit messages if those PRs aren't made against the master branch, so do you mind closing this yourself? Thanks!

[tsudukim]

Thank you! @JoshRosen