Add Vincent to authors

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

appinfo/info.xml

@@ -25,6 +25,7 @@ And in the works for the [coming versions](https://github.com/nextcloud/spreed/m
 	<author>Jennifer Piperek</author>
 	<author>Joas Schilling</author>
 	<author>Marco Ambrosini</author>
+	<author>Vincent Petry</author>
 
 	<namespace>Talk</namespace>