Config: no need to set default=None

By default oslo.cfg sets the default value as None. There is no
need to explicitly do this.

TrivialFix

Change-Id: I0e17a86084feb2767110b3cc38ce0c5ef47019a2

manila/data/helper.py

@@ -35,12 +35,10 @@ data_helper_opts = [
              "when migrating a share (seconds)."),
     cfg.StrOpt(
         'data_node_access_ip',
-        default=None,
         help="The IP of the node interface connected to the admin network. "
              "Used for allowing access to the mounting shares."),
     cfg.StrOpt(
         'data_node_access_cert',
-        default=None,
         help="The certificate installed in the data node in order to "
              "allow access to certificate authentication-based shares."),
 

manila/share/driver.py

@@ -106,7 +106,6 @@ share_opts = [
     # Replication option/s
     cfg.StrOpt(
         "replication_domain",
-        default=None,
         help="A string specifying the replication domain that the backend "
              "belongs to. This option needs to be specified the same in the "
              "configuration sections of all backends that support "