use strpos for fixed string matching

[glensc]

refs 8d18478

[glensc]

Travis build failure is not related to this PR.

PHP Fatal error:  Call to undefined method ZendTest\Mail\Protocol\SmtpPluginManagerCompatibilityTest::expectException() in /home/travis/build/zendframework/zend-mail/vendor/zendframework/zend-servicemanager/src/Test/CommonPluginManagerTrait.php on line 56
Fatal error: Call to undefined method ZendTest\Mail\Protocol\SmtpPluginManagerCompatibilityTest::expectException() in /home/travis/build/zendframework/zend-mail/vendor/zendframework/zend-servicemanager/src/Test/CommonPluginManagerTrait.php on line 56
Script phpunit --colors=always handling the test event returned with error code 255

[vaclavvanik]

Can u add test?

[Ocramius]

@vaclavvanik it's an idempotent change

[glensc]

@vaclavvanik please read the PR summary. the tests are present in commit referred.
@Ocramius indeed. made it quickly without much thinking :)

[glensc]

this test passes now

➔ phpunit test/Transport/SendmailTest.php
PHPUnit 4.8.35 by Sebastian Bergmann and contributors.

.SS...

Time: 144 ms, Memory: 6.75MB

OK, but incomplete, skipped, or risky tests!
Tests: 6, Assertions: 13, Skipped: 2.

[glensc]

the requested changes are made. travis fault is not mine.
@Ocramius your review change is till pending, accept these.

[glensc]

@weierophinney this is complete now

[Ocramius]

@glensc sorry for the long wait - I manually merged this via a6f72a1

Thanks!