Remove merge of 'params' and 'headers'
Remove merge of 'params' and 'headers'

This merge is removed for two reasons:
1. `post` doesn't merge them either
2. when re-authentication is required, the old token cookie in
`headers[:cookie]` would overwrite the newly fetched cookie as `headers`
would be handled as if it were passed to `get` after `retry`

threatagent/nessus.rb