return deep copy of ssl config (#1143)

* return deep copy of ssl config

* clone tls config

connectionpool.go

@@ -58,7 +58,8 @@ func setupTLSConfig(sslOpts *SslOptions) (*tls.Config, error) {
 
 	sslOpts.InsecureSkipVerify = !sslOpts.EnableHostVerification
 
-	return sslOpts.Config, nil
+	// return clone to avoid race
+	return sslOpts.Config.Clone(), nil
 }
 
 type policyConnPool struct {