MAINT-3520 FIXED Сall arrange(NULL, NULL) to avoid occasional drag'n'drop folders after renaming.

indra/llui/llfolderview.cpp

@@ -629,6 +629,8 @@ bool LLFolderView::startDrag()
 void LLFolderView::commitRename( const LLSD& data )
 {
 	finishRenamingItem();
+	arrange( NULL, NULL );
+
 }
 
 void LLFolderView::draw()