fixed swagger.json url

* the url to the swagger.json uses now the correct ip address.

see #225

src/docs/docs.go

@@ -1523,7 +1523,7 @@ type swaggerInfo struct {
 // SwaggerInfo holds exported Swagger Info so clients can modify it
 var SwaggerInfo = swaggerInfo{
 	Version:     "1.0",
-	Host:        "127.0.0.1:8080",
+	Host:        "",
 	BasePath:    "/",
 	Schemes:     []string{},
 	Title:       "Signal Cli REST API",