BUG/MINOR: fix nil pointer in refreshCerts

If the certificate file exists, but is not in use, crt is nil and instance.Reload panics
panic: runtime error: invalid memory address or nil pointer dereference

pkg/haproxy/certs/main.go

@@ -197,7 +197,7 @@ func refreshCerts(certs map[string]*cert, certDir string) {
 		if !crtOk || !crt.inUse {
 			logger.Error(os.Remove(path.Join(certDir, filename)))
 			delete(certs, certName)
-			instance.Reload("secret %s removed", crt.name)
+			instance.Reload("secret %s removed", certName)
 		}
 	}
 }