officeaccount 和 miniprogram 添加UseStableAK 配置项 (#788)

miniprogram/config/config.go

@@ -14,4 +14,5 @@ type Config struct {
 	Token          string `json:"token"`            // token
 	EncodingAESKey string `json:"encoding_aes_key"` // EncodingAESKey
 	Cache          cache.Cache
+	UseStableAK    bool // use the stable access_token
 }