[MM-42339] api4/license: add a nil check to not panic if server is not EE dist (#19770)

* api4/license: add a nil check to not panic if server is not EE dist

* add a test case

api4/license_test.go

@@ -262,3 +262,19 @@ func TestRequestTrialLicense(t *testing.T) {
 		CheckForbiddenStatus(t, resp)
 	})
 }
+
+func TestRequestRenewalLink(t *testing.T) {
+	th := Setup(t)
+	defer th.TearDown()
+
+	require.NotPanics(t, func() {
+		cloudImpl := th.App.Srv().Cloud
+		defer func() {
+			th.App.Srv().Cloud = cloudImpl
+		}()
+		th.App.Srv().Cloud = nil
+		resp, err := th.SystemAdminClient.DoAPIGet("/license/renewal", "")
+		CheckErrorID(t, err, "app.license.generate_renewal_token.no_license")
+		require.Equal(t, http.StatusBadRequest, resp.StatusCode)
+	})
+}