update(userspace/engine): allow overwriting rules with enabled flag only
update(userspace/engine): allow overwriting rules with enabled flag only

This allows defining rules that simply enable/disable already defined rules, like the following:
- rule: A rule enabled by default
  enabled: false
- rule: A rule disabled by default
  enabled: true

Signed-off-by: Jason Dellaluce <20c6928ffe03623fc951bdff750fdd62eb23ea4d@gmail.com>

draios/falco,draios/falco,draios/falco,draios/falco,draios/falco,draios/falco,draios/falco,draios/falco