setting domain=integer on var has no effect with solve

[rws]

While this works as expected:

sage: n = var('n')
sage: assume(n, 'integer')
sage: solve([n^2 == 3],n)
[]

this does not:

sage: forget()
sage: n = var('n', domain='integer')
sage: solve([n^2 == 3],n)
[n == -sqrt(3), n == sqrt(3)]

So, either solve should also look at the variable domain, or better, let's propagate domain settings to the assumption list.