Fix Trajectory timestamp generation

The Trajectory constructor generates timestamps using GenerateTimestamps, if those aren't provided by the caller. However, due to rounding issues, the returned timestamps sometimes lacked one timestamp.

Problem occurred while implementing Implement 'PointAt'-skill (sw/armarx/skills/control!53 - merged)

added bug label

requested review from @dreher

assigned to @uyrdb_dormanns

Could this change break something?

mentioned in merge request sw/armarx/skills/control!53 (merged)

changed the description

Looks good to me, thanks!

merged

mentioned in commit 954ff2aa