Resolves issue #3487 -- Throwing bug fix (#3522)

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## About The Pull Request

This fix removes a second increment to the dist_travelled variable. This
line appears to have caused the throwing range of items to be halved,
effectively. This fix should make it so that thrown objects go as far as
they are intended to.

## Why It's Good For The Game

Resolves the issue linked here:
shiptest-ss13/Shiptest#3487

## Changelog

:cl:
fix: fixed halved throw range
/:cl:

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code/controllers/subsystem/throwing.dm

@@ -160,8 +160,6 @@ SUBSYSTEM_DEF(throwing)
 				finalize()
 			return
 
-		dist_travelled++
-
 		if(actual_target && !(actual_target.pass_flags_self & LETPASSTHROW) && actual_target.loc == AM.loc) // we crossed a movable with no density (e.g. a mouse or APC) we intend to hit anyway.
 			finalize(TRUE, actual_target)
 			return