qsslsocket_openssl_symbols.* not compatible with libressl-2.6.1

althoug qtbase compiles without any errors there are problems linking wih libQt5Network.so.5.9.2 in some applications.

it appears that qsslsocket_openssl_symbols.* need some extra checks on LIBRESSL_VERSION_NUMBER

#define LIBRESSL_VERSION_NUMBER 0x2060100fL
#define LIBRESSL_VERSION_TEXT   "LibreSSL 2.6.1"
#define OPENSSL_VERSION_NUMBER  0x20000000L

libressl-2.6.1 has some additional checks that prevent qtnework being linked by some applications.

the linker reports:

/opt/qt5/lib/libQt5Network.so.5.9.2: warning: warning: EVP_CipherFinal is often misused, please use EVP_CipherFinal_ex and EVP_CIPHER_CTX_cleanup
collect2: error: ld returned 1 exit status

I encountered this problem when building kde://falkon which does not reference EVP_CipherFinal itself.

building another browser such as konqueror works ok.