Update library/Zend/Mail/Header/AbstractAddressList.php

because

[ErrorException]                                                             
  Notice: Undefined offset: 1 in vendor/zendframe  
  work/zendframework/library/Zend/Mail/Header/AbstractAddressList.php line 46
[#3789] Added test verifying issue

- Added test verifying issue presented in #3789
Merge branch 'patch-1' of git://github.com/axzx/zf2 into hotfix/3789
[#3789] Remove namespace qualifier from function calls
Merge branch 'hotfix/3789'

Close #3789