Add marker class for the screensharing extension to detect the NC app.

Signed-off-by: Joachim Bauch <bauch@struktur.de>

templates/index-public.php

@@ -24,7 +24,7 @@ script(
 );
 ?>
 
-<div id="app" data-roomId="<?php p($_['roomId']) ?>">
+<div id="app" class="nc-enable-screensharing-extension" data-roomId="<?php p($_['roomId']) ?>">
 	<div id="app-content" class="participants-1">
 
 		<header>

templates/index.php

@@ -24,7 +24,7 @@ script(
 );
 ?>
 
-<div id="app" data-roomId="<?php p($_['roomId']) ?>">
+<div id="app" class="nc-enable-screensharing-extension" data-roomId="<?php p($_['roomId']) ?>">
 	<div id="app-navigation" class="icon-loading">
 		<form id="oca-spreedme-add-room">
 			<input id="edit-roomname" type="text" placeholder="<?php p($l->t('Choose person …')) ?>"/>