textops: fixed get_body_part function for non-multipart contents error

[ycaner06]

Pre-Submission Checklist

• [ x] Commit message has the format required by CONTRIBUTING guide
• [ x] Commits are split per component (core, individual modules, libs, utils, ...)
• [x ] Each component has a single commit (if not, squash them into one commit)
• [x ] No commits to README files for modules (changes must be done to docbook files
  in doc/ subfolder, the README file is autogenerated)

Type Of Change

• [x ] Small bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds new functionality)
• Breaking change (fix or feature that would change existing functionality)

Checklist:

• PR should be backported to stable branches
• Tested changes locally
• Related to issue #XXXX (replace XXXX with an open issue number)

Description

get_body_part functions gives error even if content is not multipart. Fixed for non-multipart contents and set all contents for non-boundary params

[miconda]

Thanks!

[henningw]

@ycaner06 commit 3436104 don't have proper author configured (root@localhost). As it is already merged I will reply to sr-dev to have the author in the list archives. Please configure this git property correct next time, thank you.