Cleanup: remove use_normals arugment to MOD_deform_mesh_eval_get

Accessing the normals creates them on demand so there was no need
to pass an argument requesting them.

source/blender/modifiers/intern/MOD_curve.c

@@ -111,7 +111,7 @@ static void deformVerts(ModifierData *md,
 
   if (ctx->object->type == OB_MESH && cmd->name[0] != '\0') {
     /* mesh_src is only needed for vgroups. */
-    mesh_src = MOD_deform_mesh_eval_get(ctx->object, NULL, mesh, NULL, verts_num, false, false);
+    mesh_src = MOD_deform_mesh_eval_get(ctx->object, NULL, mesh, NULL, verts_num, false);
   }
 
   struct MDeformVert *dvert = NULL;