minor #10719 [Finder] Marked test skipped when ftp stream wrapper is not available (deguif)

This PR was merged into the 2.3 branch.

Discussion
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[Finder] Marked test skipped when ftp stream wrapper is not available

| Q               | A
| ---------------- | ---
| Bug fix?         | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT

This should prevent test from failing on hhvm as ftp stream wrapper is not currently implemented.
See https://github.com/facebook/hhvm/issues/2108 for more details.

Commits
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f35fc81 [Finder] Marked test skipped when ftp stream wrapper is not available

src/Symfony/Component/Finder/Tests/FinderTest.php

@@ -824,6 +824,10 @@ class FinderTest extends Iterator\RealIteratorTestCase
 
     public function testNonSeekableStream()
     {
+        if (!in_array('ftp', stream_get_wrappers())) {
+            $this->markTestSkipped(sprintf('Unavailable stream "%s".', 'ftp'));
+        }
+
         try {
             $i = Finder::create()->in('ftp://ftp.mozilla.org/')->depth(0)->getIterator();
         } catch (\UnexpectedValueException $e) {