RasdaPy_Wrong avg_cells() for collection with multiple bands (RGBSet)

[Bang Pham Huu]

A 2D collection with 3 bands is created by RasdaPy with these queries:

create collection test_rasdapy_rgb RGBSet
insert into test_rasdapy_rgb values marray x in [0:2, 0:2] values {1c, 1c, 1c}

the result from rasql query in terminal is correct:

rasql -q 'select avg_cells(c) from test_rasdapy_rgb as c' --out string
Result element 1: { 1, 1, 1 }

the result from rasql query by RasdaPy is not correct for band 2, 3

select avg_cells(test_rasdapy_rgb) from test_rasdapy_rgb

[1.0, 3.47328271065196e-310, 5.299808824e-315]