Fixes a simple typo in a template allowing tests to pass

Fix by David Denoncin

https://bugzilla.mozilla.org/show_bug.cgi?id=1644655

--- a/template/en/default/pages/release-notes.html.tmpl 2020-06-09 21:34:41.845822737 -0000
+++ b/template/en/default/pages/release-notes.html.tmpl	2020-06-09 21:05:23.515833860 -0000
@@ -45,7 +45,7 @@
 
 <h3>5.0.6</h3>
 <p>This release contains a schema change to the flagtypes table, allowing for many more flagtypes.</p>.
-<p>The flagtypes table should have been using a mediumint for several releases, but due to a bug in the schema migration code this never happened.</p>
+<p>The flagtypes table should have been using a mediumint for several releases, but due to [% terms.abug %] in the schema migration code this never happened.</p>
 
 <h3>5.0.5</h3>