Permit a deflateParams() parameter change as soon as possible.

This commit allows a parameter change even if the input data has
not all been compressed and copied to the application output
buffer, so long as all of the input data has been compressed to
the internal pending output buffer. This also allows an immediate
deflateParams change so long as there have been no deflate calls
since initialization or reset.

Obtained from: upstream (f9694097dd69354b03cb8af959094c7f260db0a1)