Fix window context in Go template
requested to merge walking-octopus/ut-app-meta-template:walking-octopus-master-patch-23700 into master
I've been writing a WhatsApp client for Ubuntu Touch, but couldn't get past the login, because the app got stuck creating the window on Nexus 5. I've tried to debug this for weeks, before finding the solution in the source code of Futify. Because the context was set to nil, it didn't wait for the client and the context to be created. If this solution doesn't apply to this example, remove the context, but keep a comment to tell future devs about this issue.