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>

C4/SIP/SIPServer.pm

@@ -1,3 +1,5 @@
+#!/usr/bin/perl
+
 package C4::SIP::SIPServer;
 
 use strict;