Fix libreoffice symlink

Dockerfile

@@ -17,7 +17,7 @@ WORKDIR LibreOffice_6.3.3.2_Linux_x86-64_deb/DEBS
 ## Install LibreOffice
 
 RUN dpkg -i *.deb
-RUN ln -s /usr/local/bin/libreoffice6.2 /usr/local/bin/libreoffice
+RUN ln -s /usr/local/bin/libreoffice6.3 /usr/local/bin/libreoffice
 
 ## Install pandoc