add missing maven compiler source and target overrides

apache-commons-digester.spec

@@ -2,7 +2,7 @@
 
 Name:          apache-%{short_name}
 Version:       2.1
-Release:       13%{?dist}
+Release:       14%{?dist}
 Summary:       XML to Java object mapping module
 License:       ASL 2.0
 URL:           http://commons.apache.org/digester/
@@ -36,7 +36,7 @@ This package contains the %{summary}.
 %mvn_file :%{short_name} %{short_name} %{name}
 
 %build
-%mvn_build
+%mvn_build -- -Dmaven.compiler.source=1.6 -Dmaven.compiler.target=1.6
 
 %install
 %mvn_install
@@ -48,6 +48,9 @@ This package contains the %{summary}.
 %doc LICENSE.txt NOTICE.txt
 
 %changelog
+* Tue Nov 05 2019 Fabio Valentini <decathorpe@gmail.com> - 2.1-14
+- Add missing maven compiler source and target overrides.
+
 * Wed Jul 24 2019 Fedora Release Engineering <releng@fedoraproject.org> - 2.1-13
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild