Fix potential nil pointer dereference in container event monitoring

[Nepomuk5665]

Summary

• Fix incorrect operator precedence in nil check that could cause panic

Description

The condition for checking container restart state in monitor.go had incorrect operator precedence.

The expression:

inspect.State != nil && inspect.State.Restarting || inspect.State.Running

is evaluated as:

(inspect.State != nil && inspect.State.Restarting) || inspect.State.Running

This means if inspect.State is nil, the inspect.State.Running check would be evaluated (because the left side of || could be false), causing a nil pointer dereference panic.

The fix adds explicit parentheses to ensure the nil check guards both state fields:

inspect.State != nil && (inspect.State.Restarting || inspect.State.Running)

Reproduction Scenario

This bug could be triggered when:

1. A container dies (triggers the events.ActionDie case)
2. ContainerInspect returns successfully but with State: nil (rare edge case)
3. The container is not restarting (inspect.State.Restarting would panic before even checking)

While Docker typically always populates the State field, defensive programming dictates that after checking for nil, both conditions should be guarded.

Testing

• All unit tests pass
• Build completes successfully