Fixed a compiler issue in OSX.
Fixed a compiler issue in OSX.

potree/PotreeConverter,kyroskoh/PotreeConverter,potree/PotreeConverter,sverhoeven/PotreeConverter,Georepublic/PotreeConverter,kyroskoh/PotreeConverter,Georepublic/PotreeConverter,potree/PotreeConverter,sverhoeven/PotreeConverter,Georepublic/PotreeConverter,eokeeffe/PotreeConverter,eokeeffe/PotreeConverter,Georepublic/PotreeConverter,potree/PotreeConverter,kyroskoh/PotreeConverter,eokeeffe/PotreeConverter,potree/PotreeConverter,sverhoeven/PotreeConverter,potree/PotreeConverter,kyroskoh/PotreeConverter,potree/PotreeConverter,sverhoeven/PotreeConverter