Bug 20999: Remove invalid 'style="block"' from OPAC templates

Bug 20999: Remove invalid 'style="block"' from OPAC templates

This patch removes an invalid attribute from OPAC template markup. There
should be no visible change to the OPAC.

To test, apply the patch and confirm that the following pages still look
correct when using various cover image sources: Coce, Amazon, Google:

 - Bibliographic detail page (opac-detail.pl)
   - The shelf browser
 - Catalog search results
 - Recent comments

Signed-off-by: Charles Farmer <charles.farmer@inLibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>