systemd notify related bug fix

On older version of systemd (systemd 219) 0 means infinity on newer
version. To make one script compatible with both versions we'll replace
infinity with 86400

error message:
```
May 11 10:09:42 jessie systemd[1]:
[/lib/systemd/system/tarantool@.service:57] Failed to parse usec_t
value, ignoring: infinity
```