Fix Travis build (RPCS3#2902)

Author: hcorion

.travis.yml

@@ -75,11 +75,12 @@ before_script:
   - make -j 3
   - # AppImage generation
   - if [ "$TRAVIS_BRANCH" = "master" ] && [ "$TRAVIS_PULL_REQUEST" = false ]; then
+      export LD_LIBRARY_PATH=/opt/qt59/lib/:$LD_LIBRARY_PATH ;
       make DESTDIR=appdir install ; find appdir/ ;
       find ../bin ;
       wget -c "https://github.com/probonopd/linuxdeployqt/releases/download/continuous/linuxdeployqt-continuous-x86_64.AppImage" ; 
       chmod a+x linuxdeployqt*.AppImage ;
-      unset QTDIR; unset QT_PLUGIN_PATH ; unset LD_LIBRARY_PATH ;
+      unset QTDIR; unset QT_PLUGIN_PATH ;
       ./linuxdeployqt*.AppImage ./appdir/usr/share/applications/*.desktop -bundle-non-qt-libs ;
       ./linuxdeployqt*.AppImage ./appdir/usr/share/applications/*.desktop -appimage ;
       find ./appdir -executable -type f -exec ldd {} \; | grep " => /usr" | cut -d " " -f 2-3 | sort | uniq ;