[gimp] data: Adapt tips.dtd for gettext changes

[Niels De Graef <nielsdg src gnome org>]

commit a3c5072a1c3a212b22db1998dc1ab29411e29f19
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Sun Jun 26 10:54:41 2022 +0200

    data: Adapt tips.dtd for gettext changes

 data/tips/gimp-tips.dtd | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/data/tips/gimp-tips.dtd b/data/tips/gimp-tips.dtd
index eb4f286908..afa923c601 100644
--- a/data/tips/gimp-tips.dtd
+++ b/data/tips/gimp-tips.dtd
@@ -9,8 +9,11 @@
 <!ENTITY % markup "(#PCDATA|b|big|tt)*">
 
 <!ELEMENT b %markup;>
+<!ATTLIST b xml:lang CDATA #IMPLIED>
 <!ELEMENT big %markup;>
+<!ATTLIST big xml:lang CDATA #IMPLIED>
 <!ELEMENT tt %markup;>
+<!ATTLIST tt xml:lang CDATA #IMPLIED>
 
 <!ELEMENT thetip %markup;>
 <!ATTLIST thetip xml:lang CDATA #IMPLIED>