[BUG] CSS code in installation via .jar file

[contra8]

Describe the bug
During installation on a headless system (Ubuntu) some plain CSS code is displayed in the console.

Expected behavior
This CSS code does not contain any necessary information for the installation process and should not be displayed.

To Reproduce
Start installation via command line:
java -jar exist-installer-5.1.1.jar -console
Immediately after start of installation, the following CSS code is displayed in the console:

body {
font-family: Verdana, Geneva, Lucida, Helvetica, sans-serif;
font-size: 13pt;
background-color: #ffffff;
}
h1 {
color: #4c4c4c;
font-size: 16pt;
}
img {
display: block;
margin: 10px 50px;
}
#divMijloc { margin: 20px 10px; margin-right: auto; text-align:center; }

Later during that same installation process, just before finishing the installation, again some CSS code is displayed in the console:

body {
font-family: Verdana, Geneva, Lucida, Helvetica, sans-serif;
font-size: 12pt;
background-color: #EAEAEA;
margin: 8px 10px;
}
h1 {
color: #4c4c4c;
font-size: 12pt;
margin: 0 0 1em 0;
}
h2 {
font-size: 12pt;
margin: 0 0 1em 0;
}
em {
color: #0000FF;
font-style: normal;
}

Context
OS: Ubuntu 12.04 TLS (headless system)
eXist-db version: 5.1.1
Java version: OpenJDK 1.8.0_111

Screenshots
Screenshots of the displayed CSS code can be found in my Dropbox here and here.

[adamretter]

I can reproduce this. I have opened an issue upstream with the IzPack installer project - https://izpack.atlassian.net/browse/IZPACK-1659