help: bad fix for missing config keys

The unknown config value will be displayed without warning or anything
to the user in the help page, which can be confusing e.g. when mixing
dash and underscore in keys. oh well

bebop/help.py

@@ -104,7 +104,7 @@ def get_help(config, plugins):
     config_list = "\n".join(
         (
             f"* {key} = {config[key]} (default {repr(DEFAULT_CONFIG[key])})"
-            if config[key] != DEFAULT_CONFIG[key]
+            if key in DEFAULT_CONFIG and config[key] != DEFAULT_CONFIG[key]
             else f"* {key} = {config[key]}"
         )
         for key in sorted(config)