[kdiff3] doc/en: Fix compile with KF5DocTolls 5.44

[Michael Reeves]

Git commit ba6c263d372916800daceaffd6a282246c10f4cd by Michael Reeves.
Committed on 30/12/2019 at 01:48.
Pushed by mreeves into branch 'master'.

Fix compile with KF5DocTolls 5.44

M  +2    -0    doc/en/index.docbook

https://invent.kde.org/kde/kdiff3/commit/ba6c263d372916800daceaffd6a282246c10f4cd

diff --git a/doc/en/index.docbook b/doc/en/index.docbook
index 3badae7..6c058aa 100644
--- a/doc/en/index.docbook
+++ b/doc/en/index.docbook
@@ -3,6 +3,8 @@
   <!ENTITY kdiff3 "<application>KDiff3</application>">
   <!ENTITY % addindex "IGNORE">
   <!ENTITY % English "INCLUDE">
+  <!-- This entity is missing from KF5DocTools 5.44 -->
+  <!ENTITY ASCII "<acronym>ASCII</acronym>">
 ]>
 
 <book lang="&language;">