Problem: connecter classes do not handle ZMQ_RECONNECT_IVL of -1 (#3163)

* Problem: connecter classes do not handle ZMQ_RECONNECT_IVL of -1

Solution: Add guards to prevent a reconnect timer from starting if ZMQ_RECONNECT_IVL is -1
(Issue 3158)

src/ipc_connecter.cpp

@@ -176,11 +176,13 @@ void zmq::ipc_connecter_t::start_connecting ()
 
 void zmq::ipc_connecter_t::add_reconnect_timer ()
 {
+    if (options.reconnect_ivl != -1) {
         int rc_ivl = get_new_reconnect_ivl ();
         add_timer (rc_ivl, reconnect_timer_id);
         socket->event_connect_retried (endpoint, rc_ivl);
         timer_started = true;
     }
+}
 
 int zmq::ipc_connecter_t::get_new_reconnect_ivl ()
 {

src/socks_connecter.cpp

@@ -268,11 +268,13 @@ void zmq::socks_connecter_t::error ()
 
 void zmq::socks_connecter_t::start_timer ()
 {
+    if (options.reconnect_ivl != -1) {
         const int interval = get_new_reconnect_ivl ();
         add_timer (interval, reconnect_timer_id);
         _status = waiting_for_reconnect_time;
         _socket->event_connect_retried (_endpoint, interval);
     }
+}
 
 int zmq::socks_connecter_t::get_new_reconnect_ivl ()
 {

src/tcp_connecter.cpp

@@ -226,11 +226,13 @@ void zmq::tcp_connecter_t::add_connect_timer ()
 
 void zmq::tcp_connecter_t::add_reconnect_timer ()
 {
+    if (options.reconnect_ivl != -1) {
         const int interval = get_new_reconnect_ivl ();
         add_timer (interval, reconnect_timer_id);
         _socket->event_connect_retried (_endpoint, interval);
         _reconnect_timer_started = true;
     }
+}
 
 int zmq::tcp_connecter_t::get_new_reconnect_ivl ()
 {

src/tipc_connecter.cpp

@@ -178,11 +178,13 @@ void zmq::tipc_connecter_t::start_connecting ()
 
 void zmq::tipc_connecter_t::add_reconnect_timer ()
 {
+    if (options.reconnect_ivl != -1) {
         int rc_ivl = get_new_reconnect_ivl ();
         add_timer (rc_ivl, reconnect_timer_id);
         socket->event_connect_retried (endpoint, rc_ivl);
         timer_started = true;
     }
+}
 
 int zmq::tipc_connecter_t::get_new_reconnect_ivl ()
 {

src/vmci_connecter.cpp

@@ -178,11 +178,13 @@ void zmq::vmci_connecter_t::start_connecting ()
 
 void zmq::vmci_connecter_t::add_reconnect_timer ()
 {
+    if (options.reconnect_ivl != -1) {
         int rc_ivl = get_new_reconnect_ivl ();
         add_timer (rc_ivl, reconnect_timer_id);
         socket->event_connect_retried (endpoint, rc_ivl);
         timer_started = true;
     }
+}
 
 int zmq::vmci_connecter_t::get_new_reconnect_ivl ()
 {