Fix product_by_location with stock_skip_warehouse and no product_ids

issue3843
review5171002
(grafted from f2f79e388f07fede7be1273ad1e64477a78eaadf)

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branch : 2.8
extra : source : f2f79e388f07fede7be1273ad1e64477a78eaadf
extra : amend_source : f7865cabec4e5de1aba3e13084698129911c07e8
Prepare release 2.8.5

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branch : 2.8
Added tag 2.8.5 for changeset 665a1716cec6

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branch : 2.8
Increase version number

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branch : 2.8