FIX init.redhat -- add second pidfile options in exec line

Fix init script for Redhat
without this fix daemon cant start with error message:
```
# service tinc restart
Shutting down Tinc:                                        [FAILED]
Starting Tinc: /usr/sbin/tincd: unrecognized argument '/var/run/tinc.pid'
Try `/usr/sbin/tincd --help' for more information.
                                                           [FAILED]
```
After applying this patch, everything was run correctly.