File is not marked as modified for host when other people are editing

[ungb]

1. Host open a portal to a file
2. Other user joins and makes edit

Expected: file is modified

Actual: file isn't modified until host clicks into file

[as-cii]

I think this will be fixed as part of atom/text-buffer#261, because when integrating remote operations we were not emitting a bunch of events that the modified icon relied on.

I'll go ahead and close this as I can't reproduce on master (which includes the aforementioned fix). As soon as Atom 1.21.0-beta2 is shipped (potentially later this week or early the next one) this will automatically resolve itself.