Fix chown syntax on deb packages

[f-galland]

Description

Our current packages throw a warning at install time about improper usage of the chown command:

Running Wazuh Indexer Post-Installation Script
chown: warning: '.' should be ':': ‘wazuh-indexer.wazuh-indexer’
chown: warning: '.' should be ':': ‘wazuh-indexer.wazuh-indexer’
chown: warning: '.' should be ':': ‘wazuh-indexer.wazuh-indexer’
chown: warning: '.' should be ':': ‘wazuh-indexer.wazuh-indexer’
chown: warning: '.' should be ':': ‘wazuh-indexer.wazuh-indexer’
chown: warning: '.' should be ':': ‘wazuh-indexer.wazuh-indexer’