Add get for system type

app/client.py

@@ -71,9 +71,9 @@ async def join_server(system_id, guild_id, channel_id):
         tags_list = [TalkgroupTag(**tag_dict) for tag_dict in sys_details.get('tags', []) if tag_dict] if sys_details.get('tags') is not None else None
 
         sys_config = ConfigGenerator(
-            type=sys_details['decode_mode'],
+            type=sys_details.get('decode_mode'),
             systemName=sys_details['name'],
-            frequencies=sys_details['frequency_list_khz'], # Assuming 'channels' is the correct field name
+            frequencies=sys_details.get('frequency_list_khz'), # Assuming 'channels' is the correct field name
             tags=tags_list,
             whitelist=sys_details.get('tag_whitelist') # Use .get for optional fields
         )