Reporting an error (with <3/5> logs) if control file not found

- Errors from logs contain more detailed pieces of information
- See gh#yast/yast-installation#86
Removed the obsolete fallback control file
Fixed path
Removed client called from the fallback contol file (only)

- This client has been showing that a fallback control file is
  in use, removed as it will never be used again
Fixed a typo in comment
Shortened GitHub reference
Merge pull request #91 from kobliha/no_default_control_file

Removed so called 'default' control file