GIT_SILENT Update Appstream for new release

org.kde.kblocks.appdata.xml

@@ -136,10 +136,10 @@
     <binary>kblocks</binary>
   </provides>
   <releases>
+    <release version="21.08.1" date="2021-09-02"/>
     <release version="21.08.0" date="2021-08-12"/>
     <release version="21.04.3" date="2021-07-08"/>
     <release version="21.04.2" date="2021-06-10"/>
-    <release version="21.04.1" date="2021-05-13"/>
   </releases>
   <content_rating type="oars-1.1"/>
 </component>