GIT_SILENT Update Appstream for new release

src/org.kde.sieveeditor.appdata.xml

@@ -135,9 +135,9 @@
   </screenshots>
   <project_group>KDE</project_group>
   <releases>
+    <release version="5.18.3" date="2021-11-04"/>
     <release version="5.18.2" date="2021-10-07"/>
     <release version="5.18.1" date="2021-09-02"/>
     <release version="5.18.0" date="2021-08-12"/>
-    <release version="5.17.3" date="2021-07-08"/>
   </releases>
 </component>