UI elements not accessible in Advanced preferences tab

[Hb---]

The advanced tab of the preferences dialog box has three issues:

1. The title is truncated even when there is enough space left
2. The "Search:" field title is off screen
3. The Add and the More buttons are off screen:

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2018-03-01 10:08:48 +0100 (Thu, 01 Mar 2018)
Build-Date:2018-03-01 09:12:13
Revision:13478
Redirecting:to URL 'https://josm.openstreetmap.de/svn/trunk':
Relative:URL: ^/trunk

Identification: JOSM/1.5 (13478 de) Linux Ubuntu 16.04.3 LTS
Memory Usage: 147 MB / 239 MB (36 MB allocated, but free)
Java version: 1.8.0_151-8u151-b12-0ubuntu0.16.04.2-b12, Oracle Corporation, OpenJDK Server VM
Screen: :0.0 1024x768
Maximum Screen Size: 1024x768
Java package: openjdk-8-jre:i386-8u151-b12-0ubuntu0.16.04.2
Program arguments: [--reset-preferences]

Last errors/warnings:
- W: Vorhandene Einstellungsdatei '<josm.pref>/preferences.xml' wird mit den Standardeinstellungen ersetzt.
- W: No configuration settings found.  Using hardcoded default values for all pools.