phablet-network fails if a VPN connection is up

[Jean-Baptiste Lallement]

when a VPN is UP (2 connections on the same devices) phablet-network fails.

sudo phablet-network -s <SOME SERIAL>
[sudo] password for XXXXXXXXXX:
Network connection file "/etc/NetworkManager/system-connections/<VPN SSID>
/etc/NetworkManager/system-connections/<WLAN SSID>" cannot be read

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: phablet-tools 1.1+15.04.20150218-0ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-7.7-generic 3.19.0
Uname: Linux 3.19.0-7-generic x86_64
ApportVersion: 2.16.2-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Mar 6 19:14:31 2015
InstallationDate: Installed on 2013-09-03 (548 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130902)
PackageArchitecture: all
SourcePackage: phablet-tools
UpgradeStatus: No upgrade log present (probably fresh install)