Pull nanomsg from our mirror instead of from github.

DEPS

 use_relative_paths = True
 
 # Dependencies on outside packages.
 #
 deps = {
   "common": "https://skia.googlesource.com/common.git@af1de867422c42855ae54ed3838c62ea445ea6b4",
 
   "third_party/externals/angle2" : "https://chromium.googlesource.com/angle/angle.git@23a8a433529d9db23882c702a29d5e594841563d",
   "third_party/externals/freetype" : "https://skia.googlesource.com/third_party/freetype2.git@VER-2-5-0-1",
   "third_party/externals/gyp" : "https://chromium.googlesource.com/external/gyp.git@3917682a16d5c19ff3576a8be0ffdb3a332954b1",
   "third_party/externals/libjpeg" : "https://chromium.googlesource.com/chromium/deps/libjpeg_turbo.git@82ce8a6d4ebe12a177c0c3597192f2b4f09e81c3",
   "third_party/externals/jsoncpp" : "https://chromium.googlesource.com/external/jsoncpp/jsoncpp.git@1afff032c83e26ddf7f2776e8b43de5ad666c1fa",
   "third_party/externals/libwebp" : "https://chromium.googlesource.com/webm/libwebp.git@3fe91635df8734b23f3c1b9d1f0c4fa8cfaf4e39",
-  "third_party/externals/nanomsg": "git://github.com/nanomsg/nanomsg.git@0.4-beta",
+  "third_party/externals/nanomsg": "https://skia.googlesource.com/third_party/nanomsg.git@0.4-beta",
 }
 
 recursedeps = [
   "common",
 ]
 
 deps_os = {
   "android": {
     "platform_tools/android/third_party/externals/expat" : "https://android.googlesource.com/platform/external/expat.git@android-4.2.2_r1.2",
     "platform_tools/android/third_party/externals/gif" : "https://android.googlesource.com/platform/external/giflib.git@android-4.2.2_r1.2",
@@ skipping 19 matching lines @@
   }
 }
 
 #hooks = [
 #  {
 #    # A change to a .gyp, .gypi, or to GYP itself should run the generator.
 #    "pattern": ".",
 #    "action": ["python", "trunk/gyp_skia"],
 #  },
 #]