TL Removal (cmss13-devs#4715)

# About the pull request
Removes the TL tag after an FTL is demoted from SL.


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
fix: fixed FTLs being demoted from SL erroneously having the tag TL in
chat.
/:cl:

code/game/jobs/job/marine/squads.dm

@@ -604,7 +604,7 @@
 		if(JOB_SQUAD_MEDIC)
 			old_lead.comm_title = "HM"
 		if(JOB_SQUAD_TEAM_LEADER)
-			old_lead.comm_title = "TL"
+			old_lead.comm_title = "FTL"
 		if(JOB_SQUAD_SMARTGUN)
 			old_lead.comm_title = "SG"
 		if(JOB_SQUAD_LEADER)