Fix campaign description template.

resources/ui/templates/campaigntemplate_EN.j2

@@ -4,6 +4,7 @@
 <p><strong style="color:orange">This campaign was created for an unknown version
 of the game.</strong></p>
 <p>You can still attempt to play this campaign but there may be game breaking
+bugs.</p>
 {% elif campaign.is_out_of_date %}
 <p><strong style="color:orange">This campaign was created for an older version
 of the game.</strong></p>