webapp/latex: improve masking of pythontex cache dir -- #3229
webapp/latex: improve masking of pythontex cache dir -- #3229

tscholl2/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc