Use Digest::SHA instead of removed Digest::SHA1

This fixes the Digest import in server.pl. Digest::SHA1 has long been
replaced by the more generic Digest::SHA.

CommModule/server.pl

@@ -12,7 +12,7 @@ use File::CounterFile;
 use Time::HiRes q(usleep);
 use IPC::Open3;
 use File::Copy;
-use Digest::SHA1 qw(sha1_hex);
+use Digest::SHA qw(sha1_hex);
 
 #Protocol version:
 my $ver=1;