Change default fd limits for single rabbitmq

As shown testing of non-HA rabbit cluster we need more FD for
cluster with 500 compute nodes as we supported.

Extrapolation of tests results for  opened FD  for RabbitMQ
===========================================================
|cmp nodes count|opened FD|FD(cmp_count)|avg FD(cmp_count)|
===========================================================
|             86|4000     |  46.51162791|46.58914729      |
|            150|7000     |  46.66666667|                 |
|            500|23294.574|             |                 |
-----------------------------------------------------------

Change-Id: I37fa0cd4440f63bcd8e6a207374d5b6f755957a8
Realted-prod: PROD-33313
2 files changed