Clarify use of insecure flag

config.go

@@ -14,6 +14,8 @@ type Config struct {
 	Lang           string   // TODO: should default to 'en'
 	Retry          int      // Number of retries for connect
 	ConnectTimeout int      // Connection timeout in seconds. Default to 15
-	Insecure       bool                                                     // set to true to allow comms without TLS
+	// Insecure can be set to true to allow to open a session without TLS. If TLS
+	// is supported on the server, we will still try to use it.
+	Insecure      bool
 	CharsetReader func(charset string, input io.Reader) (io.Reader, error) // passed to xml decoder
 }