[FIX] Collateral effect merging query params

The keep_query() function has to **keep** all or selected query parameters
or add new ones but not change them by merging those with the same name.

That unnecessary parameter merge breaks the *Change language* feature in the
website_sale module when *Website -> Customize -> Product Attribute's filters*
is enabled and there's 2 or more select type attributes created and at least
one of them is selected.

Merging params was added in:
* 8.0: commit 7759af7c4cd948f428eb4bebd72228a335cc6eab
* 9.0: commit daf8bdf688a8d7c3a8799b45f3c983a589232fa2

0 files changed, 0 insertions, 0 deletions