luci-app-aria2: Fix incorrect closing tag

Suggested-by: taeasy <88336@live.com>
[fix commit subject]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

applications/luci-app-aria2/luasrc/view/aria2/settings_header.htm

@@ -34,7 +34,7 @@
 		<%- for _, v in pairs(uilist.installed) do %>
 		<input type="button" class="cbi-button" style="margin: 0 5px;" value="<%=uilist.supported[v]%>" onclick="openWebInterface('<%=v%>');" />
 		<%- end %>
-	<p>
+	</p>
 	<% end %>
 </fieldset>