To avoid the confusing in log, change '%s' to '%q', change the question sentence to a reminding sentence.

Signed-off-by: Zen Lin(Zhinan Lin) <linzhinan@huawei.com>
Upstream-commit: 08ea03ccb9c6c671b465572e4a5c9a5d1da1fda0
Component: engine

components/engine/docker/docker.go

@@ -111,7 +111,7 @@ func main() {
 			*flTls = true
 			cert, err := tls.LoadX509KeyPair(*flCert, *flKey)
 			if err != nil {
-				log.Fatalf("Couldn't load X509 key pair: %s. Key encrypted?", err)
+				log.Fatalf("Couldn't load X509 key pair: %q. Make sure the key is encrypted", err)
 			}
 			tlsConfig.Certificates = []tls.Certificate{cert}
 		}