fiix(ingress): Fix HTTP exception arguments

Instead of raising HTTP exception, lets raise ServiceUnavailable

Non breaking change

Author: krisnova

rootfs/api/models/app.py

@@ -227,6 +227,8 @@ def create(self, *args, **kwargs):  # noqa
         try:
             # In order to create an ingress, we must first have a namespace.
             if settings.EXPERIMENTAL_NATIVE_INGRESS:
+                if ingress == "":
+                    raise ServiceUnavailable('Empty hostname')
                 try:
                     self._scheduler.ingress.get(ingress)
                 except KubeException:

rootfs/scheduler/resources/ingress.py

@@ -25,9 +25,6 @@ def get(self, name=None, **kwargs):
     def create(self, ingress, namespace, hostname):
         url = "/apis/extensions/v1beta1/namespaces/%s/ingresses" % namespace
 
-        if hostname == "":
-            raise KubeHTTPException("empty hostname value")
-
         data = {
             "kind": "Ingress",
             "apiVersion": "extensions/v1beta1",