Adds zoom to the GAL, SSG-04 and EBR. (#2810)

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## About The Pull Request

Adds the ability to zoom on the scope for a few rifles.

## Why It's Good For The Game
Encourages acting as a squad, buffs them a little. little silly that the
scope is only decorative

## Changelog

:cl:
add: The SSG-04, GAL and EBR can now use their scopes!
/:cl:

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code/modules/projectiles/guns/ballistic/automatic.dm

@@ -134,6 +134,7 @@
 	righthand_file = 'icons/mob/inhands/weapons/64x_guns_right.dmi'
 	icon_state = "ebr"
 	item_state = "ebr"
+	zoomable = TRUE
 	mag_display = TRUE
 	weapon_weight = WEAPON_MEDIUM
 	w_class = WEIGHT_CLASS_BULKY
@@ -153,6 +154,7 @@
 	fire_sound = 'sound/weapons/gun/rifle/shot.ogg'
 	icon_state = "gal"
 	item_state = "gal"
+	zoomable = TRUE
 	mag_display = TRUE
 	weapon_weight = WEAPON_MEDIUM
 	w_class = WEIGHT_CLASS_BULKY