[configdb.py]: Allow deletion of entire table from mod_config API. (sonic-net#61)

sonic-cfggen uses mod_config to write to db. mod_config API should allow
deletion of entire table instead of throwing python exception.

Signed-off-by: Praveen Chaudhary [email protected]

Author: Praveen Chaudhary

src/swsssdk/configdb.py

@@ -294,6 +294,9 @@ def mod_config(self, data):
         """
         for table_name in data:
             table_data = data[table_name]
+            if table_data == None:
+                self.delete_table(table_name)
+                continue
             for key in table_data:
                 self.mod_entry(table_name, key, table_data[key])