Change engine start error message for SFrame.
Change engine start error message for SFrame.

* There should not be a reference to GraphLab Create (this is the SFrame engine).
* There should not be a reference to Dato support (instead, we should direct users to GitHub since this is an open source project).
haijieg/SFrame,dato-code/SFrame,hoytak/SFrame,hoytak/SFrame,dato-code/SFrame,haijieg/SFrame,TobyRoseman/SFrame,turi-code/SFrame,haijieg/SFrame,ylow/SFrame,TobyRoseman/SFrame,dato-code/SFrame,ylow/SFrame,thirdwing/SFrame,haijieg/SFrame,thirdwing/SFrame,TobyRoseman/SFrame,turi-code/SFrame,dato-code/SFrame,TobyRoseman/SFrame,hoytak/SFrame,TobyRoseman/SFrame,thirdwing/SFrame,turi-code/SFrame,ylow/SFrame,TobyRoseman/SFrame,hoytak/SFrame,TobyRoseman/SFrame,dato-code/SFrame,dato-code/SFrame,ylow/SFrame,haijieg/SFrame,turi-code/SFrame,ylow/SFrame,turi-code/SFrame,hoytak/SFrame,ylow/SFrame,TobyRoseman/SFrame,thirdwing/SFrame,haijieg/SFrame,turi-code/SFrame,hoytak/SFrame,ylow/SFrame,hoytak/SFrame,thirdwing/SFrame,dato-code/SFrame,haijieg/SFrame,ylow/SFrame,thirdwing/SFrame,dato-code/SFrame,thirdwing/SFrame,thirdwing/SFrame,haijieg/SFrame,hoytak/SFrame,turi-code/SFrame,turi-code/SFrame