Update vendor github.com/lib/pq (#2752)

vendor/github.com/lib/pq/ssl_go1.7.go

@@ -0,0 +1,14 @@
+// +build go1.7
+
+package pq
+
+import "crypto/tls"
+
+// Accept renegotiation requests initiated by the backend.
+//
+// Renegotiation was deprecated then removed from PostgreSQL 9.5, but
+// the default configuration of older versions has it enabled. Redshift
+// also initiates renegotiations and cannot be reconfigured.
+func sslRenegotiation(conf *tls.Config) {
+	conf.Renegotiation = tls.RenegotiateFreelyAsClient
+}