remove mithril from config

Mods/vcmi/Content/config/english.json

@@ -1091,6 +1091,5 @@
 	"resources.core.sulfur.name" : "Sulfur",
 	"resources.core.crystal.name" : "Crystal",
 	"resources.core.gems.name" : "Gems",
-	"resources.core.gold.name" : "Gold",
-	"resources.core.mithril.name" : "Mithril"
+	"resources.core.gold.name" : "Gold"
 }

Mods/vcmi/Content/config/german.json

@@ -1084,6 +1084,5 @@
 	"resources.core.sulfur.name" : "Schwefel",
 	"resources.core.crystal.name" : "Kristall",
 	"resources.core.gems.name" : "Edelsteine",
-	"resources.core.gold.name" : "Gold",
-	"resources.core.mithril.name" : "Mithril"
+	"resources.core.gold.name" : "Gold"
 }

config/resources.json

@@ -46,12 +46,5 @@
 		"name": "Gold",
 		"price": 1
 
-	},
-	
-	"mithril": {
-		"index" : 7,
-		"name": "Mithril",
-		"price": 0
-
 	}
 }