review fix

modoboa_installer/config_dict_template.py

@@ -1,6 +1,8 @@
 import random
 import string
 
+from constants import DEFAULT_BACKUP_DIRECTORY
+
 
 def make_password(length=16):
     """Create a random password."""
@@ -441,10 +443,10 @@ ConfigDictTemplate = [
     },
     {
         "name": "backup",
-        "values": [ 
+        "values": [
             {
                 "option": "default_path",
-                "default": "./modoboa_backup/"
+                "default": DEFAULT_BACKUP_DIRECTORY
             }
         ]
     }