Remove unnecessary null pointer checks

[elfring]

An extra null pointer check is not needed in functions like the following.

• RequestImplementation destructor
• ResponseImplementation destructor

[drubinstein]

Thanks for opening this issue!

I'd rather remove the mallocs and frees and use types that implement RAII such as std::vector or std::deque if possible. I'm going to close this issue and create a new one instead about RAII.

[elfring]

I am curious then how the software development will be continued also for the topic “Use RAII instead of manual memory management”.