Description:
------------
If headers contain leading newline, iconv_mime_decode_headers return empty array instead of parsed headers array 

Reproduce code:
---------------
$headers = '
Subject: Test
From: myself@dot.com
';

print_r(iconv_mime_decode_headers($headers));

/* Note, that $headers string start with newline*/

Expected result:
----------------
Array
(
    [Subject] => Test
    [From] => myself@dot.com
)


Actual result:
--------------
Array
(
)