## What changes were proposed in this pull request?

Some link fixes for the documentation [Running Spark on Mesos](https://spark.apache.org/docs/latest/running-on-mesos.html):

* Updated Link to Mesos Frameworks (Projects built on top of Mesos)
* Update Link to Mesos binaries from Mesosphere (former link was redirected to dcos install page)

## How was this patch tested?

Documentation was built and changed page manually/visually inspected.

No code was changed, hence no dev tests.

Since these changes are rather trivial I did not open a new JIRA ticket.

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: Joachim Hereth <joachim.hereth@numberfour.eu>

Closes #18564 from daten-kieker/mesos_doc_fixes.