Update Redis client used for bucket notifications (#7213)

Current Redis client used https://github.com/garyburd/redigo/
has been archived and further development is done at
https://github.com/gomodule/redigo

This commit updates the client library accordingly.

Fixes #6392

vendor/github.com/gomodule/redigo/redis/go17.go

@@ -0,0 +1,29 @@
+// +build go1.7,!go1.8
+
+package redis
+
+import "crypto/tls"
+
+func cloneTLSConfig(cfg *tls.Config) *tls.Config {
+	return &tls.Config{
+		Rand:                        cfg.Rand,
+		Time:                        cfg.Time,
+		Certificates:                cfg.Certificates,
+		NameToCertificate:           cfg.NameToCertificate,
+		GetCertificate:              cfg.GetCertificate,
+		RootCAs:                     cfg.RootCAs,
+		NextProtos:                  cfg.NextProtos,
+		ServerName:                  cfg.ServerName,
+		ClientAuth:                  cfg.ClientAuth,
+		ClientCAs:                   cfg.ClientCAs,
+		InsecureSkipVerify:          cfg.InsecureSkipVerify,
+		CipherSuites:                cfg.CipherSuites,
+		PreferServerCipherSuites:    cfg.PreferServerCipherSuites,
+		ClientSessionCache:          cfg.ClientSessionCache,
+		MinVersion:                  cfg.MinVersion,
+		MaxVersion:                  cfg.MaxVersion,
+		CurvePreferences:            cfg.CurvePreferences,
+		DynamicRecordSizingDisabled: cfg.DynamicRecordSizingDisabled,
+		Renegotiation:               cfg.Renegotiation,
+	}
+}