POST data containing "=" lose parts of their content

Problem/Motivation

There's a bug with how the POST/GET data are handled, where the presence of "=" in the content, e.g. <a href="test">test</a>, only keeps <a href.

Steps to reproduce

Attempt to pass a variable containing "=" into the HTTP client's Data field.

Proposed resolution

Ensure the delimiter only

Remaining tasks

Provide issue fork/patch.

User interface changes

N/A