fix: Correct version format in info.xml

Signed-off-by: Christian Hartmann <chris-hartmann@gmx.de>

Author: Chartman123

appinfo/info.xml

@@ -17,7 +17,7 @@
 - **🙋 Get involved!** We have lots of stuff planned like more question types, collaboration on forms, [and much more](https://github.com/nextcloud/forms/milestones)!
 	]]></description>
 
-	<version>5.2.0.beta.0</version>
+	<version>5.2.0-beta.0</version>
 	<licence>agpl</licence>
 
 	<author>Affan Hussain</author>