Update sizes

Author: github-actions[bot]

vcmi-1.6.json

@@ -379,7 +379,7 @@
 			"https://raw.githubusercontent.com/vcmi-mods/retreat-town/vcmi-1.6/screenshots/screen2.png",
 			"https://raw.githubusercontent.com/vcmi-mods/retreat-town/vcmi-1.6/screenshots/screen3.png"
 		],
-		"downloadSize" : 19.507
+		"downloadSize" : 18.321
 	},
 	"cetatea-town" : {
 		"mod" : "https://raw.githubusercontent.com/vcmi-mods/cetatea-town/vcmi-1.6/cetatea/mod.json",