'is not 0' ==> '!= 0'; want equality check, not identity check
"is not 0" ==> "!= 0" in gentoolkitmod.py

Did someone have Coffeescript on the brain, or what?
Merge pull request #4556 from cvrebert/fix-strange-use-of-is-operator

"X is not 0" ==> "X != 0"