trajectory-msgs: Add missing dependency on geometry-msgs

This commit is based on a commit by Stefan Herbrechtsmeier [1],
but moved from after some larger refactoring to the current
release state. Hence, the dependency must still be added after
the require statement instead of before, which is possible
after the refactoring.

[1] https://github.com/herbrechtsmeier/meta-ros/commit/99426a147965c416b458de31afed9d4e3805e060

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@oss.bmw-carit.de>