added rails 2.x compatibility fix
added rails 2.x compatibility fix

Nuru/dotenv,janusnic/dotenv,customink/dotenv,sheax0r/dotenv,spore-sh/spore-rails,Neschur/dotenv,GearboxSoftware/dotenv,sorah/dotenv,bkeepers/dotenv,joemcmahon/dotenv,y-yagi/dotenv,Donavan/dotenv,slowjack2k/dotenv,cshaffer/dotenv,dkastner/dotenv,PerfectMemory/dotenv,rkachowski/dotenv,ooohiroyukiooo/dotenv