Free WOLFSSL_X509 from wolfSSL_get_peer_certificate() with wolfSSL >= 5.3.0

[cconlon]

Starting with wolfSSL 5.3.0 (wolfSSL/wolfssl@afca455), the wolfSSL_get_peer_certificate() API returns a new/duplicate WOLFSSL_X509 structure that needs to be explicitly freed with wolfSSL_X509_free().

Prior to wolfSSL 5.3.0, wolfSSL_get_peer_certificate() returned a pointer to internal memory that was freed automatically by normal native wolfSSL cleanup routines.

This shows up through some exploration with -fsanitize=address:

Indirect leak of 10 byte(s) in 1 object(s) allocated from:
    #0 0x7f5b9d305808 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:144
    #1 0x7f5a404785af in wolfSSL_Malloc wolfcrypt/src/memory.c:352
    #2 0x7f5a405296b0 in CopyDecodedToX509 src/internal.c:12942
    #3 0x7f5a4066f818 in d2i_X509orX509REQ src/x509.c:3618
    #4 0x7f5a4066f9f5 in wolfSSL_X509_d2i_ex src/x509.c:3653
    #5 0x7f5a40690c0b in wolfSSL_X509_dup src/x509.c:13671
    #6 0x7f5a4063ccff in wolfSSL_get_peer_certificate src/ssl.c:13255
    #7 0x7f5a4085f20f in Java_com_wolfssl_WolfSSLSession_getPeerCertificate (wolfssljni/lib/libwolfssljni.so+0x2620f)
    #8 0x7f5b8972ffa6  (<unknown module>)