Make the password work when we join our first channel on that server

Because we need to wait for the welcome message, when we connect to the
server, before sending the JOIN command, we need to also save the value of
the password to reuse it when we actually send the JOIN command

src/irc/irc_client.hpp

@@ -8,6 +8,7 @@
 #include <network/tcp_socket_handler.hpp>
 
 #include <unordered_map>
+#include <utility>
 #include <memory>
 #include <vector>
 #include <string>
@@ -81,7 +82,7 @@ public:
   /**
    * Send the JOIN irc command.
    */
-  void send_join_command(const std::string& chan_name, const std::string& password = "");
+  void send_join_command(const std::string& chan_name, const std::string& password);
   /**
    * Send a PRIVMSG command for a channel
    * Return true if the message was actually sent
@@ -245,12 +246,13 @@ private:
    */
   DummyIrcChannel dummy_channel;
   /**
-   * A list of chan we want to join, but we need a response 001 from
-   * the server before sending the actual JOIN commands. So we just keep the
-   * channel names in a list, and send the JOIN commands for each of them
-   * whenever the WELCOME message is received.
+   * A list of chan we want to join (tuples with the channel name and the
+   * password, if any), but we need a response 001 from the server before
+   * sending the actual JOIN commands. So we just keep the channel names in
+   * a list, and send the JOIN commands for each of them whenever the
+   * WELCOME message is received.
    */
-  std::vector<std::string> channels_to_join;
+  std::vector<std::tuple<std::string, std::string>> channels_to_join;
   /**
    * This flag indicates that the server is completely joined (connection
    * has been established, we are authentified and we have a nick)