[FIX] First person camera example's mouse initialization fixed.
[FIX] First person camera example's mouse initialization fixed.

aidinabedi/playcanvas-engine,aidinabedi/playcanvas-engine,MicroWorldwide/PlayCanvas,sereepap2029/playcanvas,playcanvas/engine,sereepap2029/playcanvas,sereepap2029/playcanvas,MicroWorldwide/PlayCanvas,guycalledfrank/engine,guycalledfrank/engine,playcanvas/engine