fix link to database schema libreoffice file

BUGS: 331141
FIXED-IN: 6.0.0

core/libs/database/item/imageinfo.h

@@ -223,7 +223,7 @@ public:
     DatabaseItem::Category category() const;
 
     /** Returns the image format / mimetype as a standardized
-     *  string (see DBSCHEMA.ODS).
+     *  string (see project/documents/DBSCHEMA.ODS).
      */
     QString format() const;