http: return headers for the last request
http: return headers for the last request

With kerberos proxy, getting /oauth/authorize first returns 401
Unauthorized and then 302 with the token after providing kerberos
credentials. However the pycurl adapter returned headers for the first
(401) response where the Location header with the token was not present.
This fix makes it return headers for the last (302) response.

DBuildService/osbs-client,bfontecc007/osbs-client,bfontecc007/osbs-client,twaugh/osbs-client,pbabinca/osbs,vrutkovs/osbs-client,projectatomic/osbs-client,twaugh/osbs-client,pbabinca/osbs,pombredanne/osbs-client,TomasTomecek/osbs,jpopelka/osbs-client,vrutkovs/osbs-client,jpopelka/osbs-client,DBuildService/osbs-client,pombredanne/osbs-client,TomasTomecek/osbs,projectatomic/osbs-client