fix control panel links, broken in Firefox (worked in Chrome)

see https://discourse.mailinabox.email/t/bug-present-for-ages/694/3

management/templates/aliases.html

@@ -7,7 +7,7 @@
 
 <h3>Add a mail alias</h3>
 
-<p>Aliases are email forwarders. An alias can forward email to a <a href="javascript:show_panel('users')">mail user</a> or to any email address.</p>
+<p>Aliases are email forwarders. An alias can forward email to a <a href="#" onclick="return show_panel('users')">mail user</a> or to any email address.</p>
 
 <form class="form-horizontal" role="form" onsubmit="do_add_alias(); return false;">
   <div class="form-group">

management/templates/users.html

@@ -32,9 +32,9 @@
 </form>
 <ul style="margin-top: 1em; padding-left: 1.5em; font-size: 90%;">
   <li>Passwords must be at least four characters and may not contain spaces.</li>
-  <li>Use <a href="javascript:show_panel('aliases')">aliases</a> to create email addresses that forward to existing accounts.</li>
+  <li>Use <a href="#" onclick="return show_panel('aliases')">aliases</a> to create email addresses that forward to existing accounts.</li>
   <li>Administrators get access to this control panel.</li>
-  <li>User accounts cannot contain any international (non-ASCII) characters, but <a href="javascript:show_panel('aliases')">aliases</a> can.</li>
+  <li>User accounts cannot contain any international (non-ASCII) characters, but <a href="#" onclick="return show_panel('aliases');">aliases</a> can.</li>
 </ul>
 
 <h3>Existing mail users</h3>