fixup (improve config.traits structure)

Snakefile

@@ -597,7 +597,7 @@ def traits_params(wildcards):
     if bias:=resolve_config_value(['traits', 'sampling_bias_correction'], wildcards):
         args += f" --sampling-bias-correction {bias}"
     if confidence:=resolve_config_value(['traits', 'confidence'], wildcards):
-        args += f" --confidence {confidence}"
+        args += f" --confidence"
     return args