OO-3620: fix issue with drake destroy, fix null fragments

src/main/java/org/olat/modules/ceditor/ui/_content/page_run.html

-#foreach($fragment in $fragments)
-	<div class="$fragment.cssClass">
-		$r.render($fragment.componentName)
-		
-	</div>
-#end
\ No newline at end of file

src/main/java/org/olat/modules/ceditor/ui/component/PageFragmentsComponent.java

@@ -47,6 +47,9 @@ public class PageFragmentsComponent extends AbstractComponent implements Compone
 	}
 
 	public List<PageFragment> getFragments() {
+		if(fragments == null) {
+			return new ArrayList<>(1);
+		}
 		return new ArrayList<>(fragments);
 	}
 

src/main/webapp/static/js/jquery/openolat/jquery.contenteditor.js

@@ -102,7 +102,6 @@
 		}).on('out', function(el, target, source) {
 			jQuery(target).removeClass('oo-accepted');
 		}).on('drop', function(el, target, source, sibling) {
-			drake.destroy();// drop trigger a reload -> clean up all and more
 			drop(el, target, source, sibling);
 		});