I used int instead of String because in MongoDBCacheStoreTest I use this method like this:
```java
catch (NumberFormatException e) {
         throw log.mongoPortIllegalValue(configurationPort);
      }
````
and configurationPort is a String coming from System.getProperty()

So we have multiples choices:
- override the mongoPortIllegalValue to have 1 signature with an int and one with a string (but the same message) I don't think it's the right choice.
- change the parameter from String to Object
- keep the call above with String.valueOf()


WDYT ?