This was reproduced in the latest version 6.0.0

Describe the bug
When the boundary has only one character boundary="-" the parts of the email are not properly extracted by \Webklex\PHPIMAP\Structure::detectParts

The email content

The value of the attachment in debugged

As we can see the Conte has been detected as a part of the attachment which is wrong

Additional context
EML example with the problem
bad_boundary.eml.zip

Do you know if there is anything that can be done here?