dtle panic when src config does not match `DestType`

    task "src" {
        KafkaConfig = {
        }
        # No DestConnectionConfig
    }
...
    task "dest" {
        DestType = "kafka"
    }

panic

    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: [signal SIGSEGV: segmentation violation code=0x2 addr=0x40 pc=0x100a99d8c]: driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: : driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: goroutine 62 [running]:: driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: github.com/actiontech/dtle/driver/mysql/mysqlconfig.(*ConnectionConfig).GetDBUri(0xc0f5e282a48f67d0?): driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: 	/Users/user0/pro0/dtle2/driver/mysql/mysqlconfig/connection.go:27 +0x1c: driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: github.com/actiontech/dtle/driver/mysql.(*Applier).InitDB(0x14000478300): driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: 	/Users/user0/pro0/dtle2/driver/mysql/applier.go:707 +0x30: driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: github.com/actiontech/dtle/driver/mysql.(*Applier).initDBConnections(0x14000478300): driver=dtle
    2023-02-23T15:15:22.615+0800 [DEBUG] client.driver_mgr.dtle: 	/Users/user0/pro0/dtle2/driver/mysql/applier.go:715 +0x2c: driver=dtle