adapted assertion text of assertMailContainsText

tests/TestCase/TestSuite/EmailTraitTest.php

@@ -218,7 +218,7 @@ class EmailTraitTest extends TestCase
             'assertMailContains' => ['assertMailContains', 'Failed asserting that \'Missing\' is in an email.', ['Missing']],
             'assertMailContainsAttachment' => ['assertMailContainsAttachment', 'Failed asserting that \'no_existing_file.php\' is an attachment of an email.', ['no_existing_file.php']],
             'assertMailContainsHtml' => ['assertMailContainsHtml', 'Failed asserting that \'Missing\' is in the html message of an email.', ['Missing']],
-            'assertMailContainsText' => ['assertMailContainsText', 'Failed asserting that \'Missing\' is in the text message of an email.', ['Missing']],
+            'assertMailContainsText' => ['assertMailContainsText', 'Failed asserting that \'Missing\' is in the text message of an email' . PHP_EOL .'was: .', ['Missing']],
             'assertMailContainsAt' => ['assertMailContainsAt', 'Failed asserting that \'Missing\' is in email #1.', [1, 'Missing']],
             'assertMailContainsHtmlAt' => ['assertMailContainsHtmlAt', 'Failed asserting that \'Missing\' is in the html message of email #1.', [1, 'Missing']],
             'assertMailContainsTextAt' => ['assertMailContainsTextAt', 'Failed asserting that \'Missing\' is in the text message of email #1.', [1, 'Missing']],