[refactor] change default dict params

As raised by kali, they can bring some bugs and avoiding it is pretty
easy.

-- Resolves: #8957

1 files changed, 4 insertions, 4 deletions

diff --git a/src/leap/soledad/common/l2db/errors.py b/src/leap/soledad/common/l2db/errors.py
index b502fc2d..d42860fe 100644
--- a/src/leap/soledad/common/l2db/errors.py
+++ b/src/leap/soledad/common/l2db/errors.py
@@ -143,10 +143,10 @@ class HTTPError(U1DBError):
 
     wire_description = None
 
-    def __init__(self, status, message=None, headers={}):
+    def __init__(self, status, message=None, headers=None):
         self.status = status
         self.message = message
-        self.headers = headers
+        self.headers = headers or {}
 
     def __str__(self):
         if not self.message:
@@ -160,8 +160,8 @@ class Unavailable(HTTPError):
 
     wire_description = "unavailable"
 
-    def __init__(self, message=None, headers={}):
-        super(Unavailable, self).__init__(503, message, headers)
+    def __init__(self, message=None, headers=None):
+        super(Unavailable, self).__init__(503, message, headers or {})
 
     def __str__(self):
         if not self.message: