fix relative @HtmlImport paths in deep folders in deployment mode

lib/build/html_import_annotation_recorder.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 library web_components.build.html_import_recorder_inliner;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:barback/barback.dart';
 import 'package:initialize/transformer.dart';
@@ skipping 61 matching lines @@
     var libPath;
     var segments = element.source.uri.pathSegments;
     var package = segments[0];
     if (bootstrapId.package == package &&
         bootstrapId.path.startsWith('${segments[1]}/')) {
       package = null;
       libPath = path.url.relative(
           path.url.joinAll(segments.getRange(1, segments.length)),
           from: path.url.dirname(path.url.join(bootstrapId.path)));
     } else if (segments[1] == 'lib') {
-      libPath = path.url.joinAll(segments.getRange(1, segments.length));
+      libPath = path.url.joinAll(segments.getRange(2, segments.length));
     } else {
       logger.error('Unable to import `${element.source.uri.path}` from '
           '${bootstrapId}.');
       return null;
     }
 
     importPaths
         .add(normalizeHtmlImportPath(originalImportPath, package, libPath));
 
     // Don't emit an InitEntry.
     return null;
   }
 }