www: ensure all href values are enclosed in single or double quotes
www: ensure all href values are enclosed in single or double quotes

AFAICT this was the only exception, an oversight from the original mustache
conversion done back in commit 107b9cdf8.

I used a local Kudu master to verify the change in the emitted HTML, and
followed a couple links in the browser to make sure everything still worked.

Change-Id: Ib1b9cc8f97390617d6b0a6e183081483ca7ad6a0
Reviewed-on: http://gerrit.cloudera.org:8080/14429
Tested-by: Kudu Jenkins
Reviewed-by: Alexey Serbin <864f6b82bd94e8dda64141d4274519ee66e0102e@cloudera.com>

helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu