Revert "aes: the init function fails when OpenSSL has AES support"

This partially reverts commit f4f2298ef3635acd031cc2ee0e71026cdcda5864
because it caused the compatibility code to call initialization routines
redundantly, leading to memory leakage with OpenSSL 1.1 and broken curl
test-suite in Fedora:

88 bytes in 1 blocks are definitely lost in loss record 5 of 8
   at 0x4C2DB8D: malloc (vg_replace_malloc.c:299)
   by 0x72C607D: CRYPTO_zalloc (mem.c:100)
   by 0x72A2480: EVP_CIPHER_meth_new (cmeth_lib.c:18)
   by 0x4E5A550: make_ctr_evp.isra.0 (openssl.c:407)
   by 0x4E5A8E8: _libssh2_init_aes_ctr (openssl.c:471)
   by 0x4E5BB5A: libssh2_init (global.c:49)
1 file changed