Fixes plasma thruster acceleration (#2980)

<!-- Write **BELOW** The Headers and **ABOVE** The comments else it may
not be viewable. -->
<!-- You can view Contributing.MD for a detailed description of the pull
request process. -->

## About The Pull Request

If you burned the expected amount of fuel you got full thrust regardless
of throttle

## Why It's Good For The Game

<!-- Please add a short description of why you think these changes would
benefit the game. If you can't justify it in words, it might not be
worth adding. -->

## Changelog

:cl:
fix: fueled thruster throttling now works right
/:cl:

<!-- Both :cl:'s are required for the changelog to work! You can put
your name to the right of the first :cl: if you want to overwrite your
GitHub username as author ingame. -->
<!-- You can use multiple of the same prefix (they're only used for the
icon ingame) and delete the unneeded ones. Despite some of the tags,
changelogs should generally represent how a player might be affected by
the changes rather than a summary of the PR's contents. -->

---------

Signed-off-by: Theos <[email protected]>

code/game/machinery/shuttle/shuttle_engine_types.dm

@@ -29,7 +29,7 @@
 	if(heat_creation)
 		heat_engine()
 	var/to_use = fuel_use * (percentage / 100) * deltatime
-	return resolved_heater.consume_fuel(to_use, fuel_type) / to_use * thrust //This proc returns how much was actually burned, so let's use that and multiply it by the thrust to get all the thrust we CAN give.
+	return resolved_heater.consume_fuel(to_use, fuel_type) / to_use * percentage / 100 * thrust //This proc returns how much was actually burned, so let's use that and multiply it by the thrust to get all the thrust we CAN give.
 
 /obj/machinery/power/shuttle/engine/fueled/return_fuel()
 	. = ..()