Bug Report: legends on panels overlaps

[kkzhang]

Describe the bug
When multiple addplots exists in a panel, their label overlaps.

To Reproduce

data["col1"] = np.random.rand(len(data))
data["col2"] = np.random.rand(len(data))

addplots = [
    mpf.make_addplot(data["col1"], label="col1", panel=1),
    mpf.make_addplot(data["col2"], label="col2", panel=1)
]

mpf.plot(data, type="candle", addplot=addplots)

Expected behavior
legends should be vertical stacked

Screenshots

Additional context
if panel=0, it's all ok.