course: fix major confusing bug -- the invitation got sent, but only when the project was created.
course: fix major confusing bug -- the invitation got sent, but only when the project was created.

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