The error means that there probably a blank line or space outside of a php code block.
This portion of the error"
output started at /home/pythoni/public_html/CMS100/Connections/localhost.php:10
suggests the problem is at line 9 or 10 of the localhost.php file. If you a re not able to spot the problem, send a copy of that file in a zip archive so I can take a look.