mining: fix for mining cooling down

Hacky thing that was already done to space. TCMB->T0C

Signed-off-by: Mloc-Argent <colmohici@gmail.com>

code/modules/mining/mine_turfs.dm

@@ -13,7 +13,7 @@ var/list/artifact_spawn = list() // Runtime fix for geometry loading before cont
 	opacity = 1
 	density = 1
 	blocks_air = 1
-	temperature = TCMB
+	temperature = T0C
 	var/mineral/mineral
 	var/mined_ore = 0
 	var/last_act = 0
@@ -402,7 +402,7 @@ var/list/artifact_spawn = list() // Runtime fix for geometry loading before cont
 	icon_state = "asteroid"
 	oxygen = 0.01
 	nitrogen = 0.01
-	temperature = TCMB
+	temperature = T0C
 	icon_plating = "asteroid"
 	var/dug = 0       //0 = has not yet been dug, 1 = has already been dug