Catch exceptions in websockets and drop the connection

src/server.cpp

@@ -259,6 +259,11 @@ private:
             }
             // unhandled/unknown message
             return lc.ws->disconnect();
+        }, [](kj::Exception&& e){
+            // server logs suggest early catching here avoids fatal exception later
+            // TODO: reproduce in unit test
+            KJ_LOG(WARNING, e.getDescription());
+            return kj::READY_NOW;
         });
     }