gives UPP SL normal bag with some basic loudout (#4127)

# About the pull request

UPP SL had only empty JIMA flag bag that is tiny and useless. Now they
get normal UPP bag with mini fire extinguisher three WP , two snacks and
on AP mag.

# Explain why it's good for the game

SL should not start with less stuff then normal soldier.


# 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:
add: UPP SL gets proper bag with mini fire extinguisher three WP
grenades , two snacks and an AP mag
/:cl:

code/modules/gear_presets/upp.dm

@@ -804,7 +804,14 @@
 /datum/equipment_preset/upp/leader/load_gear(mob/living/carbon/human/new_human)
 	var/UPPleadsidearm = rand(1,4)
 	//back
-	new_human.equip_to_slot_or_del(new /obj/item/storage/backpack/jima, WEAR_BACK)
+	new_human.equip_to_slot_or_del(new /obj/item/storage/backpack/lightpack/upp, WEAR_BACK)
+	new_human.equip_to_slot_or_del(new /obj/item/tool/extinguisher/mini, WEAR_IN_BACK) //0.66
+	new_human.equip_to_slot_or_del(new /obj/item/explosive/grenade/phosphorus/upp, WEAR_IN_BACK) //1.33
+	new_human.equip_to_slot_or_del(new /obj/item/explosive/grenade/phosphorus/upp, WEAR_IN_BACK) //2
+	new_human.equip_to_slot_or_del(new /obj/item/explosive/grenade/phosphorus/upp, WEAR_IN_BACK) //2.66
+	new_human.equip_to_slot_or_del(new /obj/item/reagent_container/food/snacks/upp, WEAR_IN_BACK) //3.33
+	new_human.equip_to_slot_or_del(new /obj/item/reagent_container/food/snacks/upp, WEAR_IN_BACK) //4
+	new_human.equip_to_slot_or_del(new /obj/item/ammo_magazine/rifle/type71/ap, WEAR_IN_BACK) //5
 	//face
 	new_human.equip_to_slot_or_del(new /obj/item/device/radio/headset/distress/UPP/command, WEAR_L_EAR)
 	//head