Fix checking if image is in media directory

Author: Bartlomiejsz

app/code/Magento/Catalog/Model/Category/FileInfo.php

@@ -76,7 +76,7 @@ private function getMediaDirectory()
     private function getBaseDirectory()
     {
         if (!isset($this->baseDirectory)) {
-            $this->baseDirectory = $this->filesystem->getDirectoryRead(DirectoryList::ROOT);
+            $this->baseDirectory = $this->filesystem->getDirectoryRead(DirectoryList::PUB);
         }
 
         return $this->baseDirectory;

app/code/Magento/Catalog/Test/Unit/Model/Category/FileInfoTest.php

@@ -57,7 +57,7 @@ protected function setUp()
 
         $this->filesystem->expects($this->any())
             ->method('getDirectoryRead')
-            ->with(DirectoryList::ROOT)
+            ->with(DirectoryList::PUB)
             ->willReturn($this->baseDirectory);
 
         $this->mime = $this->getMockBuilder(Mime::class)