nagios-nrpe: check_amavis: Update regex

I just installed a Debian Stretch with a pack mail and the check_amavis
was not checking the right regex.

Amavis is returning:
2.7.0 Ok, discarded, id=17556-09 - INFECTED: Eicar-Signature
So the regex should be:
-if ($result =~/2.7.0 Ok, discarded, id=[^,]+ - INFECTED: Eicar-Test-Signature/) {
+if ($result =~/2.7.0 Ok, discarded, id=\S+ - INFECTED: Eicar-Signature/) {

nagios-nrpe/files/plugins/check_amavis

@@ -65,7 +65,7 @@ $smtp->close();
 
 print "$result\n";
 
-if ($result =~/2.7.0 Ok, discarded, id=[^,]+ - INFECTED: Eicar-Test-Signature/) {
+if ($result =~/2.7.0 Ok, discarded, id=\S+ - INFECTED: Eicar-Signature/) {
         print "OK - All fine\n";
         exit 0;
 } else {