Fix `rlLoadComputeShaderProgram` define (#2067)

Now uses correct version.

src/rlgl.h

@@ -3759,7 +3759,7 @@ unsigned int rlLoadComputeShaderProgram(unsigned int shaderId)
 {
     unsigned int program = 0;
 
-#if defined(GRAPHICS_API_OPENGL_33)
+#if defined(GRAPHICS_API_OPENGL_43)
     GLint success = 0;
     program = glCreateProgram();
     glAttachShader(program, shaderId);