Fix shader file loading for oF < 0.8.1
Fix shader file loading for oF < 0.8.1

sewonist/ofxFX,armadillu/ofxFX,ReallyRad/ofxFX,armadillu/ofxFX,AntonioModer/ofxFX,ReallyRad/ofxFX,AntonioModer/ofxFX,sewonist/ofxFX