Description:
------------
When calling ssh2_auth_pubkey_file with $pubkeyfile or $privkeyfile starting with ~/, it destroys contents of strings (and php70 sometimes Segfaults).

Looks like it's connected with "Explode '~/paths' stopgap fix because libssh2 does not accept tilde for homedir" block in ssh2.c

Test script:
---------------
<?php

$pub = '~/.ssh/id_rsa.pub';
$priv = '~/.ssh/id_rsa';

echo "$pub\n$priv\n";

$ssh = ssh2_connect("server.com");
ssh2_auth_pubkey_file($ssh, 'root', $pub, $priv);

echo "$pub\n$priv\n";


Expected result:
----------------
[root@test 1]# php56 keyauth.php
~/.ssh/id_rsa.pub
~/.ssh/id_rsa
~/.ssh/id_rsa.pub
~/.ssh/id_rsa
[root@test 1]# php70 keyauth.php
~/.ssh/id_rsa.pub
~/.ssh/id_rsa
~/.ssh/id_rsa.pub
~/.ssh/id_rsa
[root@test 1]#


Actual result:
--------------
[root@test 1]# php56 keyauth.php
~/.ssh/id_rsa.pub
~/.ssh/id_rsa
 d_rsa.pub
▒9▒<d_rsa
[root@test 1]# php70 keyauth.php
~/.ssh/id_rsa.pub
~/.ssh/id_rsa
▒▒;▒>▒▒U▒
▒'▒d_rsa
[root@test 1]#