remove wkhtmltpdf

Initially there was a Zimbra 9 version of Nextcloud Zimlet that saved emails as PDF. But it was decided to port the Zimbra X version to Zimbra 9. That version does not support saving as pdf. Removing it from the README.

Author: Barry de Graaff

README.md

@@ -12,21 +12,6 @@ Also on Nextcloud assuming it run on Apache you must add:
       RewriteCond %{HTTP:Authorization} ^(.*)
       RewriteRule .* - [e=HTTP_AUTHORIZATION:%1]
 
-On Zimbra 9 you need to install wkhtmltopdf be sure to use it from https://wkhtmltopdf.org/downloads.html and not from CentOS  repo (unless you also want to have an X server on your mailbox server)
-
-      #CentOS 7
-      yum install xorg-x11-fonts-Type1 xorg-x11-fonts-75dpi libjpeg libXrender libXext libX11 fontconfig
-      rpm -i https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox-0.12.6-1.centos7.x86_64.rpm
-      ln -s /usr/local/bin/wkhtmltopdf /bin/wkhtmltopdf
-      
-      #Ubuntu 18
-      apt install  xfonts-base xfonts-75dpi libssl1.1  libpng16-16
-      wget https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox_0.12.6-1.bionic_amd64.deb
-      dpkg -i  wkhtmltox_0.12.1.4-2.bionic_amd64.deb
-      ln -s /usr/local/bin/wkhtmltopdf /bin/wkhtmltopdf
-
-Other operating systems: https://github.com/wkhtmltopdf/packaging/releases/tag/0.12.6-1
-
 You need to compile and install the nextcloud extension jar on the mailbox server. Suggested install location  /opt/zimbra/lib/ext/nextcloud/ and restart mailbox afterwards. You also need to deploy the Zimlet using Zimlet-CLI.
 
 ## Owh no it is realllly slow