fix bug in sagemathcloud-env variable setting.
fix bug in sagemathcloud-env variable setting.

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