Updated deferred shadows example to use new framebuffer class

data/shaders/deferredshadows/mrt.frag

@@ -22,7 +22,6 @@ void main()
 
 	// Calculate normal in tangent space
 	vec3 N = normalize(inNormal);
-	N.y = -N.y;
 	vec3 T = normalize(inTangent);
 	vec3 B = cross(N, T);
 	mat3 TBN = mat3(T, B, N);