Reduce PID finding retries and simply proc interface on linux

network/state/system_default.go

@@ -10,11 +10,6 @@ import (
 	"github.com/safing/portmaster/network/socket"
 )
 
-var (
-	lookupTries     = 20 // With a max wait of 5ms, this amounts to up to 100ms.
-	fastLookupTries = 2
-)
-
 func init() {
 	// This increases performance on unsupported system.
 	// It's not critical at all and does not break anything if it fails.