Update message

Author: cicnavi

tests/src/ValueAbstracts/KeyPairFilenameConfigTest.php

@@ -141,7 +141,7 @@ public function testGetPrivateKeyStringThrowsExceptionWhenFileCannotBeRead(): vo
 
         try {
             $this->expectException(RuntimeException::class);
-            $this->expectExceptionMessage('Could not read file');
+            $this->expectExceptionMessage('file');
             $config->getPrivateKeyString();
         } finally {
             chmod($unreadableFile, 0666);