fix(wechat): convert yuan to fen for WeChat amount (×100)

WeChat amount.total is in fen (分), but user enters yuan (元).
int(0.01) = 0 which fails WeChat's minimum 1 fen validation.
Fix: int(amount * 100)

unipay/providers/wechat.py

@@ -152,7 +152,7 @@ class WechatGateway(Gateway):
 			"out_trade_no": payload["out_trade_no"],
 			"notify_url": payload["notify_url"],
 			"amount": {
-				"total": int(payload["amount"]),
+				"total": int(payload["amount"] * 100),
 				"currency": payload.get("currency", "CNY")
 			}
 		}