Description:
------------
$binary treats truthy values (e.g. non-empty string) as true

```
$binary = 'hello';
echo md5( 'abc', $binary );
```

outputs a binary md5, instead of a hex md5, even though we didn't pass true
It should only output a binary md5 if `$binary === true`, not if `$binary == true`

As the documentation states:
>If the optional binary is set to **true**, then the md5 digest is instead returned in raw binary format with a length of 16.

# Solution
Basically what we need here is 2 things:
1) a notice, like we already have for the 1st arg:
`md5() expects parameter 2 to be bool, string given`

2) strict checking `$binary === true`, not `$binary == true`


Test script:
---------------
$binary = 'hello';
echo md5( 'abc', $binary );

Expected result:
----------------
1) a notice, like we already have for the 1st arg:
`md5() expects parameter 2 to be bool, string given`

2) strict checking `$binary === true`, not `$binary == true`
so we would get a hex md5 not a binary in this example

Actual result:
--------------
binary md5