Add missing comma in Chromoting webapp manifest.

remoting/webapp/me2mom/manifest.json

 {
   "name": "__MSG_PRODUCT_NAME__ BETA",
   "version": "1.2.UNIQUE_VERSION",
   "description": "__MSG_PRODUCT_DESCRIPTION__",
   "default_locale": "en",
   "app": {
     "launch": {
       "local_path": "choice.html"
     }
   },
   "icons": {
     "128": "chromoting128.png",
-    "48": "chromoting48.png"
+    "48": "chromoting48.png",
     "16": "chromoting16.png"
   },
   "content_scripts": [
     {
       "matches": [
         "https://talkgadget.google.com/talkgadget/blank",
         "https://talkgadget.google.com/talkgadget/blank?*"
       ],
       "js": [ "cs_oauth2_trampoline.js" ]
     }
   ],
   "permissions": [
     "tabs",
     "https://accounts.google.com/o/oauth2/*",
     "https://www.google.com/accounts/*",
     "https://www.googleapis.com/chromoting/*",
     "https://talkgadget.google.com/talkgadget/*"
   ],
   "plugins": [
     { "path": "remoting_host_plugin.dll", "public": false },
     { "path": "libremoting_host_plugin.ia32.so", "public": false },
     { "path": "libremoting_host_plugin.x64.so", "public": false },
     { "path": "remoting_host_plugin.plugin", "public": false }
   ]
 }