Avoid warning message about invalid refuse_seconds value in Mesos >=0.21...

Starting with version 0.21.0, Apache Mesos is very noisy if the filter parameter refuse_seconds is set to an invalid value like `-1`.
I have seen systems with millions of log lines like
```
W0420 18:00:48.773059 32352 hierarchical_allocator_process.hpp:589] Using the default value of 'refuse_seconds' to create the refused resources filter because the input value is negative
```
in the Mesos master INFO and WARNING log files.
Therefore the CoarseMesosSchedulerBackend should set the default value for refuse seconds (i.e. 5 seconds) directly.
This is no problem for the fine-grained MesosSchedulerBackend, as it uses the value 1 second for this parameter.

Author: mweindel <m.weindel@usu-software.de>

Closes #5597 from MartinWeindel/master and squashes the following commits:

2f99ffd [mweindel] Avoid warning message about invalid refuse_seconds value in Mesos >=0.21.