Alb addEntriesToAcl() bug fix

[linw2015]

修复Alb的addEntriesToAcl调用报错。

修复前如下调用时：

Alb::v20200616()->addEntriesToAcl()
    ->withAclId("xxx")
    ->withAclEntries([
        [
            "Entry" => "xxx",
            "Description" => "xxx"
        ]
    ]);

报错：

In Sign.php line 96: urlencode() expects parameter 1 to be string, array given

[CLAassistant]

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