Bug 28054: Reinstate the shebang in SIPServer.pm

Bug 28054: Reinstate the shebang in SIPServer.pm

Bug 26673 renoved the shebang from SIPServer.pm. This was an error
SIPServer.pm is a program not a perl module, and needs the shebang
for the OS to assign an interpreter unless the command line
calls it as an argument to perl. Restore the shebang

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit dfe3753deeddb40610a27ccc48ad71110c2bb350)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>