fix: Bump version on backport

Signed-off-by: Joas Schilling <coding@schilljs.com>

appinfo/info.xml

@@ -18,7 +18,7 @@
 * 🌉 **Sync with other chat solutions** With [Matterbridge](https://github.com/42wim/matterbridge/) being integrated in Talk, you can easily sync a lot of other chat solutions to Nextcloud Talk and vice-versa.
 ]]></description>
 
-	<version>21.0.2</version>
+	<version>21.1.0-dev.1</version>
 	<licence>agpl</licence>
 
 	<author>Anna Larch</author>