Bug 8255: allow local cover images to be cached

At the moment, local cover images cannot be cached by the web browser
or any intermediate reverse proxies. This results in an unnecessary
load on the server, and is entirely unnecessary.

Signed-off-by: Dobrica Pavlinusic <dpavlin@rot13.org>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>

catalogue/image.pl

@@ -92,8 +92,7 @@ if ( C4::Context->preference("LocalCoverImages") ) {
 }
 print $data->header(
     -type            => $mimetype,
-    -'Cache-Control' => 'no-store',
-    -expires         => 'now',
+    -expires         => '+30m',
     -Content_Length  => length($image)
 ), $image;
 

opac/opac-image.pl

@@ -92,8 +92,7 @@ if ( C4::Context->preference("OPACLocalCoverImages") ) {
 }
 print $data->header(
     -type            => $mimetype,
-    -'Cache-Control' => 'no-store',
-    -expires         => 'now',
+    -expires         => '+30m',
     -Content_Length  => length($image)
 ), $image;