fix void connections

Author: cmnrd

include/reactor-cpp/connection.hh

@@ -53,7 +53,11 @@ public:
     return [this](const BasePort& port) {
       // We know that port must be of type Port<T>*
       auto& typed_port = reinterpret_cast<const Port<T>&>(port); // NOLINT
-      this->schedule(std::move(typed_port.get()));
+      if constexpr (std::is_same<T, void>::value) {
+        this->schedule();
+      } else {
+        this->schedule(std::move(typed_port.get()));
+      }
     };
   }