Switch jsoncpp DEPS to github mirror

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 222 matching lines @@
   'src/third_party/scons-2.0.1':
    Var('chromium_git') + '/native_client/src/third_party/scons-2.0.1.git' + '@' + '1c1550e17fc26355d08627fbdec13d8291227067',
 
   'src/third_party/webrtc':
     Var('chromium_git') + '/external/webrtc/trunk/webrtc.git' + '@' + 'f814f6db65486838a7d00ba126dc0b305a86e00f',
 
   'src/third_party/openmax_dl':
     Var('chromium_git') + '/external/webrtc/deps/third_party/openmax.git' + '@' +  Var('openmax_dl_revision'),
 
   'src/third_party/jsoncpp/source':
-    Var('chromium_git') + '/external/jsoncpp/jsoncpp.git' + '@' + 'ab1e40f3bce061ea6f9bdc60351d6cde2a4f872b', # from svn 248
+    Var('chromium_git') + '/external/github.com/open-source-parsers/jsoncpp.git' + '@' + 'f572e8e42e22cfcf5ab0aea26574f408943edfa4', # from svn 248
 
   'src/third_party/libyuv':
     Var('chromium_git') + '/external/libyuv.git' + '@' + 'd204db647e591ccf0e2589236ecea90330d65a66', # from svn revision 1171
 
   'src/third_party/smhasher/src':
     Var('chromium_git') + '/external/smhasher.git' + '@' + 'e87738e57558e0ec472b2fc3a643b838e5b6e88f',
 
   'src/third_party/libaddressinput/src':
     Var('chromium_git') + '/external/libaddressinput.git' + '@' + '61f63da7ae6fa469138d60dec5d6bbecc6ab43d6',
 
@@ skipping 532 matching lines @@
     # corresponding .py files have already been deleted.
     'name': 'remove_stale_pyc_files',
     'pattern': 'src/tools/.*\\.py',
     'action': [
         'python',
         'src/tools/remove_stale_pyc_files.py',
         'src/tools',
     ],
   },
 ]