Updated preload register according to P5 0.7.2
Updated preload register according to P5 0.7.2

In the latest P5 version, `prototype.registerPreloadMethod` requires two parameters, see reference: https://github.com/processing/p5.js/blob/master/developer_docs/creating_libraries.md#use-registerpreloadmethod-to-register-names-of-methods-with-p5-that-may-be-called-in-preload

bmoren/p5.geolocation