[BUG] [epicli upgrade] Filebeat stops working when legacy Elasticsearch (v6) is used for storing logs

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Describe the bug
Before Epiphany v0.5 there was no logging role but elasticsearch role was used for storing logs.
After running epicli upgrade on Epiphany cluster v0.4.5 Filebeat was upgraded to 7.8.1 and service stopped working because groups.logging was undefined. There was the following error in syslog:

Exiting: error initializing publisher: empty array accessing 'output.elasticsearch.hosts' (source:'/etc/filebeat/filebeat.yml')

To Reproduce
Steps to reproduce the behavior:
Run epicli upgrade for cluster created by Epiphany v0.4

Expected behavior
Filebeat should not be upgraded to version 7.x if there is no Elasticsearch v7.x for storing logs.

Config files
n/a

OS
any

Cloud Environment
any

Additional context
n/a

[przemyslavic]

Checked:

• upgrade from 0.4.5: filebeat update was skipped ✔️

• upgrade from 0.5.5: filebeat updated to 7.8.1 ✔️