Single files are only accessible when they have a numeric index

[hollodotme]

Currently the following method signature only allows access to numeric indexed files.

public function getOneFile( string $fieldKey, int $fileIndex = 0 );

So if a file is submitted with a string index like this:

<input type="file" name="files[file1]">

it it not accessible by the method above.

Change the method signature to:

public function getOneFile( string $fieldKey, $fileIndex = 0 );

So the file index can either be an integer or a string.

[hollodotme]

Note: We cannot change the parameters type to string, because this would be a BC break.