style: gofumpt all the things (#9829)

Literally `gofumpt -w .` from the top level dir. Guaranteed to be minor
style changes only and nothing else.

@imsodin per request?

lib/discover/debug.go

@@ -10,6 +10,4 @@ import (
 	"github.com/syncthing/syncthing/lib/logger"
 )
 
-var (
-	l = logger.DefaultLogger.NewFacility("discover", "Remote device discovery")
-)
+var l = logger.DefaultLogger.NewFacility("discover", "Remote device discovery")

lib/discover/global_test.go

@@ -244,6 +244,7 @@ type fakeAddressLister struct{}
 func (*fakeAddressLister) ExternalAddresses() []string {
 	return []string{"tcp://0.0.0.0:22000"}
 }
+
 func (*fakeAddressLister) AllAddresses() []string {
 	return []string{"tcp://0.0.0.0:22000", "tcp://192.168.0.1:22000"}
 }