don't show 'first' when link is same as 'previous' button

figured later i should have fixed the 'first' button as well, no point in showing it when the back button points to the same page.
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Fix falling unit tests in SonataAdminExtensionTest
Merge pull request #1385 from pulzarraider/timezone_unittest_fix

Fix falling unit tests in SonataAdminExtensionTest
Fix NativeLabelTranslatorStrategy whitespace bug
Update composer.json
Merge pull request #1384 from EmmanuelVella/preview

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Merge pull request #1386 from pulzarraider/native_label_translator_fix

Fix NativeLabelTranslatorStrategy whitespace bug
Merge pull request #1367 from sjopet/patch-5

don't show 'first' when link is same as 'previous' button
Merge branch 'sonata/master'

Conflicts:
	composer.json