Simplify process_connection_writes condition

And comment explaining that we there's something more precise but more
complex available.

src/connection.hpp

@@ -338,8 +338,8 @@ private:
 
   // Direct access methods for Server
   int getFd() const { return fd_; }
-  bool hasMessages() const { return !messages_.empty(); }
-  bool shouldClose() const { return closeConnection_; }
+  bool has_messages() const { return !messages_.empty(); }
+  bool should_close() const { return closeConnection_; }
   size_t getEpollIndex() const { return epoll_index_; }
   const int fd_;
   const int64_t id_;