cmatrix : floating point exception when terminal height is < 4

[Gamer204]

On Linux Mint 17.3, when running cmatrix v. 1.2a-4 in a terminal of a height < 4, it crashes with a floating point exception.

Steps for reproducing the bug :
1. Open a terminal
2. Resize it to have less than 4 chars height
3. Launch cmatrix

The bug also occurs when reproducing steps in the order 1-3-2.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: cmatrix 1.2a-4
ProcVersionSignature: Ubuntu 3.19.0-32.37~14.04.1-generic 3.19.8-ckt7
Uname: Linux 3.19.0-32-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
CurrentDesktop: X-Cinnamon
Date: Fri Mar 11 12:20:36 2016
InstallationDate: Installed on 2016-01-09 (61 days ago)
InstallationMedia: Linux Mint 17.3 "Rosa" - Release amd64 20151128
SourcePackage: cmatrix
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.