Revert "Simplify GlossaryTerm model error messages"
Revert "Simplify GlossaryTerm model error messages"

This reverts commit e2bab0cc5c76352cfedad92c7da26293dda0b5f1.

I think this commit is what caused [Travis Build 3262](https://travis-ci.org/github/MushroomObserver/mushroom-observer/builds/724515973) failure

MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer,MushroomObserver/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer,MushroomObserver/mushroom-observer