Merge pull request zendframework/zendframework#2048 from mheleniak/ze…

…nd_mail_fixes

[Zend\Mail] fixed buggy test case

test/Header/SubjectTest.php

@@ -27,7 +27,7 @@ public function testHeaderFolding()
         $subject->setSubject($string);
 
         $expected = wordwrap($string, 78, "\r\n ");
-        $test     = $subject->getFieldValue();
+        $test     = $subject->getFieldValue(Header\HeaderInterface::FORMAT_ENCODED);
         $this->assertEquals($expected, $test);
     }
 }