fix obj shader to remove uniforms

shaders/obj.vp

@@ -1,7 +1,4 @@
 
-uniform mat4 projection;
-uniform mat4 modelview;
-
 attribute vec3 pos;
 attribute vec3 normal;
 
@@ -10,7 +7,7 @@ varying vec3 normal_i;
 
 void main(void)
 {
-    gl_Position = projection * modelview * vec4(pos, 1);
+    gl_Position = gl_ModelViewProjectionMatrix * vec4(pos, 1);
     pos_i = gl_Position.xyz;
-    normal_i = normal;
+    normal_i = gl_NormalMatrix * normal;
 }