Add Wayland Continuous Scrolling to the Xournal++ config

Author: AgenttiX

xournalpp/settings.xml

@@ -260,6 +260,10 @@
       <attribute name="deviceClass" type="int" value="2"/>
       <attribute name="deviceSource" type="int" value="1"/>
     </data>
+    <data name="Wayland Continuous Scrolling">
+      <attribute name="deviceClass" type="int" value="1"/>
+      <attribute name="deviceSource" type="int" value="7"/>
+    </data>
     <data name="Wayland Pointer">
       <attribute name="deviceClass" type="int" value="1"/>
       <attribute name="deviceSource" type="int" value="0"/>