timesync: Keep trying to connect even if the socket cannot be opened

This makes sure that after a server could not be contacted due to a
socket error, other (possibly working) NTP servers in the list of
configured NTP servers are (re-)tried.

Fixes #25728.

src/timesync/timesyncd-manager.c

@@ -119,8 +119,10 @@ static int manager_send_request(Manager *m) {
         m->event_timeout = sd_event_source_unref(m->event_timeout);
 
         r = manager_listen_setup(m);
-        if (r < 0)
-                return log_warning_errno(r, "Failed to set up connection socket: %m");
+        if (r < 0) {
+                log_warning_errno(r, "Failed to set up connection socket: %m");
+                return manager_connect(m);
+        }
 
         /*
          * Set transmit timestamp, remember it; the server will send that back