Merge pull request #9350 from piwik/no_orange_headermessage_piwikdemo

Do not show header message in orange on demo piwik when update is available

plugins/Morpheus/stylesheets/uibase/_headerMessage.less

@@ -9,7 +9,7 @@
   font-size: 14px;
   border-radius: 4px;
 
-  &.update_available .title {
+  &.update_available:not(.isPiwikDemo) .title {
     color: #CA8100;
     font-weight: bold;
   }