Add myself as contributor in AUTHORS

Author: jakub-vavra-cz

AUTHORS

@@ -25,6 +25,7 @@ DNF-PLUGINS-CORE CONTRIBUTORS
     David Michael <fedora.dm0@gmail.com>
     François Rigault <francois.rigault@amadeus.com>
     Hedayat Vatankhah <hedayat.fwd@gmail.com>
+    Jakub Vavra <jvavra@redhat.com>
     Jeff Smith <whydoubt@gmail.com>
     Lubomir Rintel <lkundrak@v3.sk>
     Luigi Toscano <luigi.toscano@tiscali.it>