Most active agent is not displayed

[AlexRuiz7]

Wazuh	Splunk	Rev
4.3	8.1.4	4301

Description
The information for the most active agent in the agents section is broken and does not show the correct agent, showing a zero instead.

Steps to reproduce

1. Go to Agents'
2. See that Most active agent shows a 0 instead of the Agent's name
3. Click on the Most Active Agent (0)
4. See cannot read properties of undefined error

Screenshots

[AlexRuiz7]

Related issue #1098