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?

cmd/strelaysrv/session.go

@@ -68,7 +68,6 @@ func findSession(key string) *session {
 	ses, ok := pendingSessions[key]
 	if !ok {
 		return nil
-
 	}
 	delete(pendingSessions, key)
 	return ses