Set public_url() protocol based on use_https

If use_https is true, prefix public URLs with https. Otherwise use
http as before.

S3/S3Uri.py

@@ -90,10 +90,13 @@ def is_dns_compatible(self):
         return check_bucket_name_dns_support(Config.Config().host_bucket, self._bucket)
 
     def public_url(self):
+        public_url_protocol = "http"
+        if Config.Config().use_https:
+            public_url_protocol = "https"
         if self.is_dns_compatible():
-            return "http://%s.%s/%s" % (self._bucket, Config.Config().host_base, self._object)
+            return "%s://%s.%s/%s" % (public_url_protocol, self._bucket, Config.Config().host_base, self._object)
         else:
-            return "http://%s/%s/%s" % (Config.Config().host_base, self._bucket, self._object)
+            return "%s://%s/%s/%s" % (public_url_protocol, Config.Config().host_base, self._bucket, self._object)
 
     def host_name(self):
         if self.is_dns_compatible():