Use SO_REUSEPORT for Admin

Closes #1726 #1723 #1787

lib/ProxySQL_Admin.cpp

@@ -3374,7 +3374,11 @@ __end_while_pool:
                                         c_split_2(sn, ":" , &add, &port);
                                 }
 
+#ifdef SO_REUSEPORT
+				int s = ( atoi(port) ? listen_on_port(add, atoi(port), 128, true) : listen_on_unix(add, 128));
+#else
 				int s = ( atoi(port) ? listen_on_port(add, atoi(port), 128) : listen_on_unix(add, 128));
+#endif
 				if (s>0) { fds[nfds].fd=s; fds[nfds].events=POLLIN; fds[nfds].revents=0; callback_func[nfds]=0; socket_names[nfds]=strdup(sn); nfds++; }
 				if (add) free(add);
 				if (port) free(port);