Revert "BUG/MINOR: ssl: fix potential memory leak in ssl_sock_load_dh_params()"

Revert "BUG/MINOR: ssl: fix potential memory leak in ssl_sock_load_dh_params()"

This reverts commit 0ea4c23ca754c3e6c005b67403a0619ca17d4587.

Certain very simple confs randomly segfault upon startup with openssl 1.0.2
with this patch, which seems to indicate a use after free. Better drop it
and let valgrind complain about the potential leak.

Also it's worth noting that the man page for SSL_CTX_set_tmp_dh() makes no
mention about whether or not the element should be freed, and the example
provided does not use it either.

This fix should be backported to 1.6 and 1.5 where the patch was just
included.