Blocked? Headers may be wrong...

Problem/Motivation

Behaviour on local environment differs from prod/dev/stage

It seems that the module passes all the headers from the outside to the service url.
In our case this led to two differnt failures:

1. Bad content length: Local it was Apache - in the the Plugin function calculateHeaders() there was no $header['content_length']. It worked fine
   On NginX $header['content_length'] was set to 0 which led to an error.
2. Request was blocked: We could avoid this by removing all headers except 'host' in function calculateHeaders()

Proposed resolution

Give User a Hint to remove all Headers (besides 'host')

Remaining tasks

User interface changes

API changes

Data model changes

Greetings from Cologne !