Segfault on saving preferences

[Dima]

Steps to reproduce:
1) Open preferences
2) Input IP range in Network tab, press Add
3) Click OK or Apply

dmesg says
[ 2829.339000] iptux[12290]: segfault at 0 ip 00007fe557e9c646 sp 00007ffe625860a8 error 4 in libc-2.27.so[7fe557deb000+1e7000]

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: iptux 0.7.4-1
ProcVersionSignature: Ubuntu 4.15.0-47.50-generic 4.15.18
Uname: Linux 4.15.0-47-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: LXDE
Date: Sat Apr 6 21:12:29 2019
EcryptfsInUse: Yes
InstallationDate: Installed on 2018-06-11 (299 days ago)
InstallationMedia: Lubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: iptux
UpgradeStatus: No upgrade log present (probably fresh install)