Replace use of deprecated functionality (related to building as an externals package)

[korydraughn]

From externals build failure:

/externals/mungefs1.0.5-0_src/mungefs/message_broker.hpp:81:30: error: 'send' is deprecated: from 4.3.1, use send taking message_t and send_flags [-Werror,-Wdeprecated-declarations]
            while(!skt_ptr_->send( msg ) ) {
                             ^
/externals/cppzmq4.8.1-1_src/opt/irods-externals/cppzmq4.8.1-1/include/zmq.hpp:1861:5: note: 'send' has been explicitly marked deprecated here
    ZMQ_CPP11_DEPRECATED("from 4.3.1, use send taking message_t and send_flags")
    ^
/externals/cppzmq4.8.1-1_src/opt/irods-externals/cppzmq4.8.1-1/include/zmq.hpp:87:35: note: expanded from macro 'ZMQ_CPP11_DEPRECATED'
#define ZMQ_CPP11_DEPRECATED(msg) ZMQ_DEPRECATED(msg)
                                  ^
/externals/cppzmq4.8.1-1_src/opt/irods-externals/cppzmq4.8.1-1/include/zmq.hpp:65:31: note: expanded from macro 'ZMQ_DEPRECATED'
#define ZMQ_DEPRECATED(msg) [[deprecated(msg)]]
                              ^

Temporary fix used by externals: -Wno-deprecated-declarations