Problem: gssapi_mechanism_base_t initialisation misses one param

Solution: pass the session as well as the options

src/gssapi_client.cpp

@@ -43,7 +43,7 @@
 zmq::gssapi_client_t::gssapi_client_t (session_base_t *session_,
                                        const options_t &options_) :
     mechanism_base_t (session_, options_),
-    gssapi_mechanism_base_t (options_),
+    gssapi_mechanism_base_t (session_, options_),
     state (call_next_init),
     token_ptr (GSS_C_NO_BUFFER),
     mechs (),

src/gssapi_server.cpp

@@ -46,7 +46,7 @@ zmq::gssapi_server_t::gssapi_server_t (session_base_t *session_,
                                        const std::string &peer_address_,
                                        const options_t &options_) :
     mechanism_base_t (session_, options_),
-    gssapi_mechanism_base_t (options_),
+    gssapi_mechanism_base_t (session_, options_),
     zap_client_t (session_, peer_address_, options_),
     state (recv_next_token),
     security_context_established (false)