To remove the vertical line from the itineraries displayed in trip outline tab use below given CSS.

For this go to Admin Panel > Appearance > Customize > Additional CSS and paste below given CSS:
CSS to remove the vertical line :
.timeline-contents .col:last-of-type .tc-content, .timeline-contents .col:last-of-type .tc-heading { border-right-color: transparent; border-left-color: transparent; }