Fix php_strip_whitespace bugginess, fixes #3030

src/Composer/Autoload/ClassMapGenerator.php

@@ -115,7 +115,7 @@ class ClassMapGenerator
         $traits = version_compare(PHP_VERSION, '5.4', '<') ? '' : '|trait';
 
         try {
-            $contents = php_strip_whitespace($path);
+            $contents = @php_strip_whitespace($path);
         } catch (\Exception $e) {
             throw new \RuntimeException('Could not scan for classes inside '.$path.": \n".$e->getMessage(), 0, $e);
         }