Bug 22551: Stray "//" appears at bottom of opac-detail.tt

Bug 22551: Stray "//" appears at bottom of opac-detail.tt

Removes a couple stray "//<![CDATA[" like comments which are artifacts of other
code that since been removed. One of the comments causes two forward slashes to
appear at the bottom of each OPAC detail page.

Testing plan:

- enable SocialNetworks
- visit any OPAC detail page, observe "//" at bottom of page
- apply patch
- revisit page, slashes should be gone

Signed-off-by: Hayley Mapley <hayleymapley@catalyst.net.nz>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>