Fix flawed logic when detecting same listener type
The older version of the code was reporting that listeners are going to be of the same type after reconfiguration when switching from DoT to HTTPS listener, making BIND abort its executions.
That was happening due to the flaw in logic due to which the code could consider a current listener and a configuration for the new one to be of the same type (DoT) even when the new listener entry is explicitly marked as HTTP.
The checks for PROXY in between the configuration were masking that behaviour, but when porting it to 9.18 (when there is no PROXY support), the behaviour was exposed.
Now the code mirrors the logic in 'interface_setup()' closely (as it was meant to).