Added m4 to BuildRequires

Resolves: rhbz#1619111

postfix.spec

@@ -45,7 +45,7 @@
 Name: postfix
 Summary: Postfix Mail Transport Agent
 Version: 3.3.1
-Release: 1%{?dist}
+Release: 2%{?dist}
 Epoch: 2
 Group: System Environment/Daemons
 URL: http://www.postfix.org
@@ -97,7 +97,7 @@ Patch10: pflogsumm-1.1.5-ipv6-warnings-fix.patch
 # Determine the different packages required for building postfix
 BuildRequires: libdb-devel, perl-generators, pkgconfig, zlib-devel
 BuildRequires: systemd-units, libicu-devel, libnsl2-devel
-BuildRequires: gcc
+BuildRequires: gcc, m4
 
 %{?with_ldap:BuildRequires: openldap-devel}
 %{?with_sasl:BuildRequires: cyrus-sasl-devel}
@@ -736,6 +736,10 @@ fi
 %endif
 
 %changelog
+* Mon Aug 20 2018 Jaroslav Škarvada <jskarvad@redhat.com> - 2:3.3.1-2
+- Added m4 to BuildRequires
+  Resolves: rhbz#1619111
+
 * Mon Jul  9 2018 Jaroslav Škarvada <jskarvad@redhat.com> - 2:3.3.1-1
 - New version
   Resolves: rhbz#1548222