snap for eog triggers: cannot change mount namespace

[fcole90]

When I try to run eog snap I get the following error:
```
$ eog
main.go:224: cannot change mount namespace of snap "eog" according to change mount (/run/user/1000/doc/by-app/snap.eog /run/user/1000/doc none bind,rw,x-snapd.ignore-missing 0 0): cannot inspect "/run/user/1000/doc": lstat /run/user/1000/doc: transport endpoint is not connected

(eog:8412): EOG-WARNING **: 18:36:54.857: Error loading Eog typelib: Typelib file for namespace 'Eog', version '3.0' not found

(eog:8412): Gtk-WARNING **: 18:36:54.861: cannot open display: :0
```

snap forum: https://forum.snapcraft.io/t/eog-eye-of-gnome-snap-error-cannot-change-mount-namespace/8909?u=fcole90

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: snapd 2.34.2+18.04
ProcVersionSignature: Ubuntu 4.15.0-42.45-generic 4.15.18
Uname: Linux 4.15.0-42-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CurrentDesktop: GNOME
Date: Sun Dec 9 18:37:28 2018
InstallationDate: Installed on 2017-08-21 (475 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170820)
SourcePackage: snapd
UpgradeStatus: No upgrade log present (probably fresh install)

[Zygmunt Krynicki (zyga)]

It looks like a problem with the document portal. James can you please have a look?