Make LIGHT_VEC affect 2D shadows again

drivers/gles2/shaders/canvas.glsl

@@ -414,7 +414,6 @@ FRAGMENT_SHADER_CODE
 		color *= light;
 
 #ifdef USE_SHADOWS
-		light_vec = light_uv_interp.zw; //for shadows
 		float angle_to_light = -atan(light_vec.x, light_vec.y);
 		float PI = 3.14159265358979323846264;
 		/*int i = int(mod(floor((angle_to_light+7.0*PI/6.0)/(4.0*PI/6.0))+1.0, 3.0)); // +1 pq os indices estao em ordem 2,0,1 nos arrays

drivers/gles3/shaders/canvas.glsl

@@ -549,7 +549,6 @@ FRAGMENT_SHADER_CODE
 		color *= light;
 
 #ifdef USE_SHADOWS
-		light_vec = light_uv_interp.zw; //for shadows
 		float angle_to_light = -atan(light_vec.x, light_vec.y);
 		float PI = 3.14159265358979323846264;
 		/*int i = int(mod(floor((angle_to_light+7.0*PI/6.0)/(4.0*PI/6.0))+1.0, 3.0)); // +1 pq os indices estao em ordem 2,0,1 nos arrays