!29 change %systemd_requires to %{?systemd_requires}

From: @duyiwei7w 
Reviewed-by: @zengwefeng 
Signed-off-by: @zengwefeng

iptables.spec

@@ -2,7 +2,7 @@
 %global legacy_actions %{_libexecdir}/initscripts/legacy-actions
 Name:		  iptables
 Version:	  1.8.7
-Release:	  3
+Release:	  4
 Summary:	  IP packet filter administration utilities
 License:	  GPLv2 and Artistic Licence 2.0 and ISC
 URL:		  https://www.netfilter.org/
@@ -21,7 +21,7 @@ Requires:         %{name}-libs = %{version}-%{release}
 
 Requires(post):   %{_sbindir}/update-alternatives
 Requires(postun): %{_sbindir}/update-alternatives
-%systemd_requires
+%{?systemd_requires}
 
 Provides:         iptables-utils iptables-services
 Obsoletes:        iptables-utils iptables-services 
@@ -315,6 +315,9 @@ fi
 %{_mandir}/man8/xtables-legacy*
 
 %changelog
+* Tue Mar 01 2022 duyiwei <duyiwei@kylinos.cn> - 1.8.7-4
+- change %systemd_requires to %{?systemd_requires}
+
 * Fri Nov 26 2021 xihaochen<xihaochen@huawei.com> - 1.8.7-3
 - Type:bugfix
 - ID:NA