Ricochet won't launch on Ubuntu Mate

[Jon "The Nice Guy" Spriggs]

When trying to launch ricochet-im on Ubuntu Mate 18.04, I get this message:

```
jon@dispatch$ ricochet

(ricochet:27997): GLib-GIO-ERROR **: 09:57:45.564: No GSettings schemas are installed on the system
Trace/breakpoint trap (core dumped)
```

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ricochet-im 1.1.4-2build1
ProcVersionSignature: Ubuntu 4.15.0-45.48-generic 4.15.18
Uname: Linux 4.15.0-45-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CurrentDesktop: MATE
Date: Thu Feb 21 09:58:11 2019
InstallationDate: Installed on 2018-06-21 (244 days ago)
InstallationMedia: Ubuntu-MATE 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: ricochet-im
UpgradeStatus: No upgrade log present (probably fresh install)

[Jon "The Nice Guy" Spriggs (jontheniceguy)]

Further commentary from "whoopsie":

Title: richochet crashed with signal 5 in g_object_new_valist()

Could someone who has access to "whoopsie" add any pertinent details, e.g. stack trace? I can't really copy-and-paste from whoopsie :(