EnvUtils: fix documentation comment in header.
EnvUtils: fix documentation comment in header.

The header referred to the 'getenv' function via its previous name,
'getEnvVariable'. Fix the comment to reflect the current state of affairs.

Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble