Changes some 1s and 0s to TRUE and FALSE (#1967)

code/datums/diseases/advance/advance.dm

@@ -31,7 +31,7 @@
 	var/list/properties = list()
 	var/list/symptoms = list() // The symptoms of the disease.
 	var/id = ""
-	var/processing = 0
+	var/processing = FALSE
 
 	// The order goes from easy to cure to hard to cure.
 	var/static/list/advance_cures = 	list(
@@ -76,7 +76,7 @@
 	if(symptoms && symptoms.len)
 
 		if(!processing)
-			processing = 1
+			processing = TRUE
 			for(var/datum/symptom/S in symptoms)
 				S.Start(src)