By default a retry limit of 17 exists. When the limit is reached buffered
logs are discarded. To avoid this, we disable the retry limit. The risk of
bringing down the host by filling the Fluent data docker volume is managed
by the maximum buffer size which is 2GB by default.

In summary, after this change, the net behaviour is that Fluentd should
buffer up to a maximum of 2GB of logs locally, and attept to post them to
the Monasca Log API at intervals not exceeding 30 minutes.

Closes-Bug: #1855702
Change-Id: I0d5a3dab29635c00411f4f51e5a0721726df2abd