[FIX] onMailetException should catch jvm Error

`onMailetException` has had no impact upon `NoSuchMethodError`.

server/mailet/mailetcontainer-impl/src/main/java/org/apache/james/mailetcontainer/impl/ProcessorImpl.java

@@ -79,7 +79,7 @@ public void process(Mail mail) throws Exception {
                      .build()) {
             MailetPipelineLogging.logBeginOfMailetProcess(mailet, mail);
             mailet.service(mail);
-        } catch (Exception | NoClassDefFoundError me) {
+        } catch (Throwable me) {
             ex = me;
             String onMailetException = null;