cubicweb #2154654 still buggy remove_cookie [validation pending]

because expires is computed to 0 and the Cookie class interpret that has no expires.

this leads to empty cookies instead. It used to work before e8091b415ad8 for people no using UTC time...

priorityimportant
typebug
done in3.14.3
load0.100
load left0.000
closed by#eff4fe02ec64 [req cookie] fix remove_cookie expires which was leading to expires computed to 0 in set_cookie and the Cookie class interpret that has no expires. Closes #2154654