Fix invalid syntax

Change-Id: I1b74214f3251ecba7c6e4f7336736b9a6732a12b
Reviewed-on: https://gerrit.libreoffice.org/52446Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

xmlscript/dtd/dialog.dtd

@@ -242,7 +242,7 @@
 <!ATTLIST dlg:img %default-attributes;
                   dlg:src CDATA #IMPLIED
                   dlg:scale-image %boolean; #IMPLIED
-                  dlg:scale-mode (none|isotropic|anisotropic); #IMPLIED
+                  dlg:scale-mode (none|isotropic|anisotropic) #IMPLIED
                   dlg:tabstop %boolean; #IMPLIED
                   >