Revert "Merge branch 'hotfix/1016'"

This reverts commit 8de79bd95055248aff1bce9d07e2e6e3a3fa8b98, reversing
changes made to bd42cd612efa62520ac2d54a5517e40fed64070c.
Fixed example `Generating a formatted HTTP Request from a Request object`

Putting requests post data into requests content. `$request->toString()` returns now the expected output with post parameters.