[MM-37108] Fix possible nil dereference in team edition (#17933)

* Fix possible nil dereference

* Fix translation

* Switch to StatusForbidden

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/license_test.go

@@ -229,4 +229,12 @@ func TestRequestTrialLicense(t *testing.T) {
 		require.Equal(t, "api.license.add_license.unique_users.app_error", resp.Error.Id)
 		require.False(t, ok)
 	})
+
+	th.App.Srv().LicenseManager = nil
+	t.Run("trial license should fail if LicenseManager is nil", func(t *testing.T) {
+		ok, resp := th.SystemAdminClient.RequestTrialLicense(1)
+		CheckForbiddenStatus(t, resp)
+		require.False(t, ok)
+		require.Equal(t, "api.license.upgrade_needed.app_error", resp.Error.Id)
+	})
 }