change DESKTOP env setting on startup
change DESKTOP env setting on startup

Summary:
From Enlightenment 17 to Enlightenment.

Seems e17 keeps popping up...
rEdb6aeef2b1a9c831fa0901e499dd8f73ff733836
rEec1cd25cfe666665b9e5641c91d3ad1fd2f9f11c

Reviewers: zmike

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D2147

rvandegrift/e,tizenorg/platform.upstream.enlightenment,rvandegrift/e,tasn/enlightenment,FlorentRevest/Enlightenment,tasn/enlightenment,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,rvandegrift/e,tizenorg/platform.upstream.enlightenment,FlorentRevest/Enlightenment,FlorentRevest/Enlightenment