license: add libepubgen

Change-Id: I38e30fb45aed7d2b8f39348e92afeb6a6f85ef6e
Reviewed-on: https://gerrit.libreoffice.org/69525
Tested-by: Jenkins
Reviewed-by: Andras Timar <andras.timar@collabora.com>

readlicense_oo/license/license.xml

@@ -690,6 +690,12 @@
         the terms of the license below:</p>
         <p><a href="#a__MPL_version_2">Jump to MPL Version 2.0</a></p>
     </div>
+    <div class="EPUBGEN" >
+        <h2>libepubgen</h2>
+        <p>The following software may be included in this product: libepubgen. Use of any of this software is governed
+        by the terms of the license below:</p>
+        <p><a href="#a__MPL_version_2">Jump to MPL Version 2.0</a></p>
+    </div>
     <h2>libe-book</h2>
     <p>The following software may be included in this product: libe-book. Use of any of this software is governed by
     the terms of the license below:</p>