fix(systems/github): Filter: get open and closed issues if no according filter was set

src/main/java/de/hftstuttgart/unifiedticketing/systems/github/GithubFilter.java

@@ -48,6 +48,10 @@ public class GithubFilter extends Filter<GithubTicket, GithubFilter>
 
         HttpUrl.Builder urlBuilder = requestBuilder.build().url().newBuilder();
 
+        // set default values before checking user filters,
+        // to match default behaviour
+        urlBuilder.addQueryParameter("state", "all");
+
         for (Map.Entry<String, Object> mapEntry : setFilters.entrySet())
         {
             String f = mapEntry.getKey();