Demote deltarpm to weak dependencies

Signed-off-by: Igor Gnatenko <ignatenko@redhat.com>

dnf.spec

@@ -28,7 +28,7 @@
 
 Name:           dnf
 Version:        2.7.5
-Release:        6%{?dist}
+Release:        7%{?dist}
 Summary:        Package manager forked from Yum, using libsolv as a dependency resolver
 # For a breakdown of the licensing, see PACKAGE-LICENSING
 License:        GPLv2+ and GPLv2 and GPL
@@ -128,7 +128,9 @@ Requires:       python2-gpg
 BuildRequires:  pyliblzma
 Requires:       pyliblzma
 Requires:       %{name}-conf = %{version}-%{release}
-Requires:       deltarpm
+%if ! (0%{?rhel} && 0%{?rhel} <= 7)
+Recommends:     deltarpm
+%endif
 Requires:       python2-hawkey >= %{hawkey_version}
 Requires:       python2-libcomps >= %{libcomps_version}
 Requires:       python2-librepo >= %{librepo_version}
@@ -165,7 +167,9 @@ BuildRequires:  python3-nose
 BuildRequires:  python3-gpg
 Requires:       python3-gpg
 Requires:       %{name}-conf = %{version}-%{release}
-Requires:       deltarpm
+%if ! (0%{?rhel} && 0%{?rhel} <= 7)
+Recommends:     deltarpm
+%endif
 Requires:       python3-hawkey >= %{hawkey_version}
 Requires:       python3-iniparse
 Requires:       python3-libcomps >= %{libcomps_version}
@@ -373,6 +377,9 @@ popd
 %endif
 
 %changelog
+* Thu Feb 08 2018 Igor Gnatenko <ignatenko@redhat.com> - 2.7.5-7
+- Demote deltarpm to weak dependencies
+
 * Wed Feb 07 2018 Fedora Release Engineering <releng@fedoraproject.org> - 2.7.5-6
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild