Fix the typeof check

Encountered this bug when I tried to update an app that was generating Blaze warnings about the deprecated old-style helper to a 0.9.4 RC. The problem is that the type of the string `'Log'` is being checked rather than the value of the `Log` variable, which obviously returns true, and then the code breaks on the `&& Log` check, which is undefined.
fix another typeof
Merge branch 'pr-2807' into devel