timeshift.appdata.xml is invalid

[dampfwal3477]

The appdata file is invalid and displays (only) croatian instead of the system's Lang.

The specification says:

In MetaInfo files, this tag (<description/>) should be translated by-paragraph. For enumerations, items are translated individually as well, and not the whole enumeration block. This means that in a translated file, only <p/> and <li/>elements may carry an xml:lang property.

The metainfo file puts xml:lang on the surrounding <description/> element, not the <p/> elements.