select_traces returns all traces when selector=0

[dmpozharskiy]

The select_traces function fetches all traces when using selector=0.

The bug is at https://github.com/plotly/plotly.py/blob/master/packages/python/plotly/plotly/basedatatypes.py#L1144 where the selector is overwritten by an empty dict in this case.

A minimum code snippet is:

fig = go.Figure()
fig.add_trace(go.Scatter(x=[0, 1], y=[0, 1], name="trace0"))
fig.add_trace(go.Scatter(x=[0, 1], y=[0, 1], name="trace1"))

for trace in fig.select_traces(selector=0):
    print(trace["name"])
    
for trace in fig.select_traces(selector=1):
    print(trace["name"])

The output is:

trace0
trace1

trace1