The optional property __time_to_live__ is always filled in message, also when the LifeTime <= 0.
Change this code:
```
result.Add("time_to_live", LifeTime.ToString());
```
into
```
if (LifeTime > 0)
{
result.Add("time_to_live", Convert.ToString(LifeTime));
}
```
Change this code:
```
result.Add("time_to_live", LifeTime.ToString());
```
into
```
if (LifeTime > 0)
{
result.Add("time_to_live", Convert.ToString(LifeTime));
}
```
