ssl_client2: initialize all structures, so that we can call *_free() in case of error
ssl_client2: initialize all structures, so that we can call *_free() in case of error

In ssl_client2, initialize at the beginning all the structures
that are used in the program. This ensures that calls to
functions like x509_free(), rsa_free() and ssl_free()
do not cause a segmentation fault or other undesired behaviour.

theatrus/tropicssl,appunite/tropicssl,theatrus/tropicssl,appunite/tropicssl