Return correct error codes from storage adapter

no issue

- malformed paths such as http://localhost:2368/content/images/2018/02/%c0%af were throwing 500 errors, instead of 500 errors
- this code catches the error and handles it correctly

core/server/adapters/storage/LocalFileStorage.js

@@ -123,6 +123,14 @@ class LocalFileStore extends StorageBase {
                         }));
                     }
 
+                    if (err.statusCode === 400) {
+                        return next(new common.errors.BadRequestError({err: err}));
+                    }
+
+                    if (err.statusCode === 403) {
+                        return next(new common.errors.NoPermissionError({err: err}));
+                    }
+
                     return next(new common.errors.GhostError({err: err}));
                 }