Add missing dependency to sdk-build.

dart.gyp

 # Copyright (c) 2012, 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.
 
 {
   'targets': [
     {
       'target_name': 'compiler',
       'type': 'none',
       'dependencies': [
@@ skipping 18 matching lines @@
       'type': 'none',
       'dependencies': [
         'runtime/dart-runtime.gyp:dart',
         'dart2js',
       ],
       'actions': [
         {
           'action_name': 'create_sdk_py',
           'inputs': [
             '<!@(["python", "tools/list_files.py", "\\.dart$", "lib"])',
+            '<!@(["python", "tools/list_files.py", "import_.*\\.config$", "lib/config"])',
             'tools/create_sdk.py',
             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
             '<(PRODUCT_DIR)/dart2js',
             '<(PRODUCT_DIR)/dart2js.bat',
           ],
           'outputs': [
             '<(PRODUCT_DIR)/dart-sdk/create.stamp',
           ],
           'action': [
             'python',
@@ skipping 53 matching lines @@
     },
     {
       'target_name': 'api_docs',
       'type': 'none',
       'dependencies': [
         'utils/apidoc/apidoc.gyp:api_docs',
       ],
     }
   ],
 }