Change some random variable indexes that cause doctest failures if doctests are run in a different order. #12395
Description
Texture variables in 3d plotting and some symbolic variables used by maxima have variable names that depend on the order they were created. This patch changes the number to a ...
CC: @robertwb
Component: doctest coverage
Author: David Roe
Reviewer: Karl-Dieter Crisman
Merged: sage-5.0.beta3
Issue created by migration from https://trac.sagemath.org/ticket/12395