made changes in edit tank info

src/models/tanks.js

@@ -9,8 +9,7 @@ const ObjectId = Schema.Types.ObjectId;
 const code = Math.floor(100000 + Math.random() * 900000);
 const RoleSchema = new Schema({ name: String });
 const tanksSchema = new mongoose.Schema({
-
-    userName: { type: String, default: null },
+    customerId: { type: String, default: null },
     tankName: { type: String, default: null },
     blockName: { type: String, default: null },
     capacity: { type: String, default: null },