The fetcher's "saved opportunities" and "fetched opportunities" lines now name the source

internal/fetcher/fetcher_test.go

@@ -921,9 +921,12 @@ func TestSaveSkipsNewOpportunities(t *testing.T) {
 	if !skipped(s) {
 		t.Error("a new matching opportunity wasn't skipped")
 	}
+	// Both lines name the source.
 	for _, want := range []string{
+		"msg=\"saved opportunities\" source=FindATender component=fetcher",
 		"skipped_opportunities=1",
-		"msg=\"skipped new opportunity\" component=fetcher uuid=ocds-1 filter=IT",
+		"msg=\"skipped new opportunity\" source=FindATender component=fetcher " +
+			"uuid=ocds-1 filter=IT",
 	} {
 		if !strings.Contains(logged.String(), want) {
 			t.Errorf("log has no %q:\n%s", want, logged.String())