Attempt to read property "nodeValue" on null

[hsklia]

Hello
When plist contain empty key and value, the library raise excception (CFPropertyList.php:373):

<key></key>
<string></string>

Plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key></key>
<string></string>
<key>BatchAPIKey</key>
<string>...</string>
<key>BuildMachineOSBuild</key>
<string>...</string>
...
</dict>
</plist>