Revert "fix: prevent pipeline errors from killing Reactor subscription (#205)"

This reverts commit 72315ae.

Author: gfukushima

src/main/java/org/ethereum/beacon/discovery/pipeline/PipelineImpl.java

@@ -29,18 +29,7 @@ public class PipelineImpl implements Pipeline {
   public synchronized Pipeline build() {
     started.set(true);
     for (EnvelopeHandler handler : envelopeHandlers) {
-      pipeline =
-          pipeline.doOnNext(
-              envelope -> {
-                try {
-                  handler.handle(envelope);
-                } catch (Throwable t) {
-                  LOG.warn(
-                      "Unexpected error in pipeline handler {}",
-                      handler.getClass().getSimpleName(),
-                      t);
-                }
-              });
+      pipeline = pipeline.doOnNext(handler::handle);
     }
     Flux.from(pipeline)
         .onErrorContinue(

src/main/java/org/ethereum/beacon/discovery/pipeline/handler/HandshakeMessagePacketHandler.java

@@ -151,13 +151,6 @@ public void handle(Envelope envelope) {
               packet, session.getNodeRecord(), session.getState()),
           ex);
       markHandshakeAsFailed(envelope, session);
-    } catch (Throwable t) {
-      LOG.warn(
-          "Unexpected error while processing handshake [{}] from node {}",
-          packet,
-          session.getNodeRecord(),
-          t);
-      markHandshakeAsFailed(envelope, session);
     }
   }