Base URL ending in slash breaks filter subscription HTML email links

If JIRA's base URL ends with a slash, eg. "http://10.60.1.96:8085/" instead of "http://10.60.1.96:8085", then issue links in filter subscription emails (only in the HTML format) will break, with URLs of the form "//browse/<key>".

If you view the email source (in Thunderbird), it contains:

...
<base href="http://10.60.1.96:8085">
...
<td class="nav issuekey">    <a href="//browse/TP-1">TP-1</a>
....

which isn't valid. Simply by removing the trailing slash from the base URL, this changes to:

...
<base href="http://10.60.1.96:8085">
...
<td class="nav issuekey">    <a href="/browse/TP-1">TP-1</a>
....