Restore GitHub functionality

My guess is that GitHub changed something here recently, which is why it
no longer worked without the explicit arguments

service/github.go

@@ -35,11 +35,13 @@ func (gh *GitHub) Generate() (string, []Entry, error) {
 	prs := make([]Entry, 0)
 
 	state := "merged"
+	isString := "is:pull-request"
 	if gh.Issues {
 		state = "closed"
+		isString = "is:issue"
 	}
 
-	query := fmt.Sprintf(`repo:%s is:%s milestone:"%s"`, gh.Repo, state, gh.Milestone)
+	query := fmt.Sprintf(`repo:%s %s is:%s milestone:"%s"`, gh.Repo, isString, state, gh.Milestone)
 	p := 1
 	perPage := 100
 	for {
@@ -89,7 +91,12 @@ func (gh *GitHub) Contributors() (ContributorList, error) {
 	gh.initClient(ctx)
 
 	contributorsMap := make(map[string]bool)
-	query := fmt.Sprintf(`repo:%s is:merged milestone:"%s"`, gh.Repo, gh.Milestone)
+	isString := "is:pull-request"
+	if gh.Issues {
+		isString = "is:issue"
+	}
+
+	query := fmt.Sprintf(`repo:%s %s is:merged milestone:"%s"`, gh.Repo, isString, gh.Milestone)
 	p := 1
 	perPage := 100
 	for {