Hello,
I have installed OwnCloud and I am currently using it well. However, our phpworks and stack has getenv disabled by default. Is there any negative impact on this or any reason why you are not using $_SERVER ?
You're probably referring to https://doc.owncloud.org/server/latest/admin_manual/configuration_server/security_setup_warnings.html#the-test-with-getenv-path-only-returns-an-empty-response ?
If yes this is completely unrelated to $_SERVER and can be ignored. ownCloud will choose sane defaults which should work on most environments out there.