Min server 28

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

appinfo/info.xml

@@ -50,7 +50,7 @@
 	<screenshot>https://raw.githubusercontent.com/nextcloud/forms/main/screenshots/forms3.png</screenshot>
 
 	<dependencies>
-		<nextcloud min-version="26" max-version="27" />
+		<nextcloud min-version="28" max-version="28" />
 	</dependencies>
 
 	<settings>