Fixes intel squad "Unauthorized access detected" (cmss13-devs#4457)

# About the pull request

Fixes intel squad "Unauthorized access detected" pop up that occurs when
trying to use the squad HUD

# Explain why it's good for the game

bug bad


# 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: Morrow
fix: Fixed intel squad "Unauthorized access detected"
/:cl:

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

@@ -185,7 +185,7 @@
 	use_stripe_overlay = FALSE
 	equipment_color = "#053818"
 	minimap_color = MINIMAP_SQUAD_INTEL
-	radio_freq = null
+	radio_freq = PUB_FREQ
 
 	roundstart = FALSE
 	prepend_squad_name_to_assignment = FALSE