Fix typo on send documentation re: nullification

doc/zmq_msg_send.txt

@@ -35,7 +35,7 @@ below for a detailed description.
 
 The _zmq_msg_t_ structure passed to _zmq_msg_send()_ is nullified during the
 call. If you want to send the same message to multiple sockets you have to copy
-it using (e.g. using _zmq_msg_copy()_).
+it (e.g. using _zmq_msg_copy()_).
 
 NOTE: A successful invocation of _zmq_msg_send()_ does not indicate that the
 message has been transmitted to the network, only that it has been queued on

doc/zmq_sendmsg.txt

@@ -31,7 +31,7 @@ below for a detailed description.
 
 The _zmq_msg_t_ structure passed to _zmq_sendmsg()_ is nullified during the
 call. If you want to send the same message to multiple sockets you have to copy
-it using (e.g. using _zmq_msg_copy()_).
+it (e.g. using _zmq_msg_copy()_).
 
 NOTE: A successful invocation of _zmq_sendmsg()_ does not indicate that the
 message has been transmitted to the network, only that it has been queued on