[FIX] ResourceLoader.request works if you don't supply a progress function
[FIX] ResourceLoader.request works if you don't supply a progress function

sereepap2029/playcanvas,H1Gdev/engine,aidinabedi/playcanvas-engine,3DGEOM/engine,MicroWorldwide/PlayCanvas,aidinabedi/playcanvas-engine,RainsSoft/engine,nizihabi/engine,SuperStarPL/engine,nizihabi/engine,sanyaade-teachings/engine,horryq/engine-1,RainsSoft/engine,SuperStarPL/engine,horryq/engine-1,shinate/engine,guycalledfrank/engine,SuperStarPL/engine,sereepap2029/playcanvas,maxwellalive/engine,guycalledfrank/engine,sereepap2029/playcanvas,3DGEOM/engine,playcanvas/engine,sanyaade-teachings/engine,3DGEOM/engine,playcanvas/engine,maxwellalive/engine,horryq/engine-1,MicroWorldwide/PlayCanvas,shinate/engine,H1Gdev/engine,RainsSoft/engine,maxwellalive/engine,nizihabi/engine,shinate/engine,sanyaade-teachings/engine