Fixing `PropelConfiguration` for syslog'ing. (#1175)
Fixing `PropelConfiguration` for syslog'ing. (#1175)

* Fixing `PropelConfiguration` for syslog'ing.

Without this, it throws:
```
  [Symfony\Component\Config\Definition\Exception\InvalidConfigurationException]  
  Unrecognized option "facility" under "propel.runtime.log.defaultLogger"   
```

At runtime, without this configuration option, it throws:
```
PHP Fatal error:  Uncaught exception 'UnexpectedValueException' with message 'Unknown facility value "" given' in /vendor/monolog/monolog/src/Monolog/Handler/AbstractSyslogHandler.php:88
```

... when using "syslog" configuration.

* Without "ident" it throws a NOTICE.

```
PHP Notice:  Undefined index: ident in /vendor/propel/propel/src/Propel/Runtime/ServiceContainer/StandardServiceContainer.php on line 494
```

cristianoc72/Propel2,propelorm/Propel2,ikeyan/Propel2,peter17/Propel2,mhitza/Propel2,propelorm/Propel2,peter17/Propel2,mhitza/Propel2,ikeyan/Propel2,cristianoc72/Propel2