QueuedFSM example does not compile

[n-burger]

With the latest changes to etl::message_packet, the QueuedFSM example does not compile anymore:

[ 50%] Building CXX object CMakeFiles/queued_fsm.dir/QueuedFSM.cpp.o
In file included from /home/etl/examples/QueuedFSM/QueuedFSM.cpp:34:
/home/etl/examples/QueuedFSM/../../include/etl/queue.h: In instantiation of ‘void etl::iqueue<T, MEMORY_MODEL>::emplace(Args&& ...) [with Args = {const etl::imessage&}; T = etl::message_packet<Message1, Message2, Message3, Message4>; long unsigned int MEMORY_MODEL = 2]’:
/home/etl/examples/QueuedFSM/QueuedFSM.cpp:107:20:   required from here
/home/etl/examples/QueuedFSM/../../include/etl/queue.h:348:7: error: call of overloaded ‘message_packet(const etl::imessage&)’ is ambiguous
  348 |       ::new (&p_buffer[in]) T(etl::forward<Args>(args)...);
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/etl/examples/QueuedFSM/../../include/etl/message_router.h:59,
                 from /home/etl/examples/QueuedFSM/../../include/etl/fsm.h:62,
                 from /home/etl/examples/QueuedFSM/QueuedFSM.cpp:35:
/home/etl/examples/QueuedFSM/../../include/etl/message_packet.h:99:14: note: candidate: ‘etl::message_packet<TMessageTypes>::message_packet(TMessage&&, etl::enable_if_t<(! is_same_v<typename std::remove_reference<_Up>::type, etl::message_packet<TMessageTypes> >), int*>) [with TMessage = const etl::imessage&; TMessageTypes = {Message1, Message2, Message3, Message4}; etl::enable_if_t<(! is_same_v<typename std::remove_reference<_Up>::type, etl::message_packet<TMessageTypes> >), int*> = int*; typename std::remove_reference<_Up>::type = const etl::imessage]’
   99 |     explicit message_packet(TMessage&& msg, etl::enable_if_t<!etl::is_same_v<etl::remove_reference_t<TMessage>, etl::message_packet<TMessageTypes...>>, int*> p = nullptr)
      |              ^~~~~~~~~~~~~~
/home/etl/examples/QueuedFSM/../../include/etl/message_packet.h:85:16: note: candidate: ‘etl::message_packet<TMessageTypes>::message_packet(TMessage&&) [with TMessage = const etl::imessage&; <template-parameter-2-2> = int; TMessageTypes = {Message1, Message2, Message3, Message4}]’
   85 |       explicit message_packet(TMessage&& msg)
      |                ^~~~~~~~~~~~~~
/home/etl/examples/QueuedFSM/../../include/etl/message_packet.h:135:5: note: candidate: ‘etl::message_packet<TMessageTypes>::message_packet(etl::message_packet<TMessageTypes>&&) [with TMessageTypes = {Message1, Message2, Message3, Message4}]’
  135 |     message_packet(message_packet&& other)
      |     ^~~~~~~~~~~~~~
/home/etl/examples/QueuedFSM/../../include/etl/message_packet.h:124:5: note: candidate: ‘etl::message_packet<TMessageTypes>::message_packet(const etl::message_packet<TMessageTypes>&) [with TMessageTypes = {Message1, Message2, Message3, Message4}]’
  124 |     message_packet(const message_packet& other)
      |     ^~~~~~~~~~~~~~
make[2]: *** [CMakeFiles/queued_fsm.dir/build.make:76: CMakeFiles/queued_fsm.dir/QueuedFSM.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:83: CMakeFiles/queued_fsm.dir/all] Error 2

[jwellbelove]

Fixed 20.29.2