saving passwords for vpn connections

[Demian Gheorghe Calin]

For a vpn connection, I want to save only one of the passwords (ex. the group password) and the other password (the user password) to be asked at connection.
When I want to connect, both passwords are asked instead of only the user password.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: network-manager 0.9.8.8-0ubuntu7.3
ProcVersionSignature: Ubuntu 3.16.0-46.62~14.04.1-generic 3.16.7-ckt15
Uname: Linux 3.16.0-46-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.23
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Feb 3 11:14:49 2017
EcryptfsInUse: Yes
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2015-05-12 (632 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
IpRoute:
 default via 192.168.0.250 dev eth0 proto static
 192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.9 metric 1
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2015-06-18T15:23:56.451313
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth0 802-3-ethernet connected /org/freedesktop/NetworkManager/Devices/1
 wlan0 802-11-wireless disconnected /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.8.8 connected enabled enabled enabled enabled enabled