[Chromoting] Improve the text on the buttons in the connection-failed dialog.

remoting/webapp/_locales/en/messages.json

 {
   "ACCESS_CODE": {
     "message": "Access code",
     "description": "Label for the access code entry box. This is where the client user enters the code that permits access to the host."
   },
   "ACCESS_CODE_TIMER": {
     "message": "This access code will expire in $timeout$",
     "description": "Text displayed when the access code is due to time out within 30 seconds.",
     "placeholders": {
       "timeout": {
@@ skipping 294 matching lines @@
     "description": "Web-app description. Displayed in Chromium's extensions page."
   },
   "PRODUCT_NAME": {
     "message": "Chromoting BETA",
     "description": "The product name. Displayed in various Chromium pages, including the New Tab page, and displayed prominently on the app's main page."
   },
   "RECONNECT": {
     "message": "Reconnect",
     "description": "Label for button to reconnect to the previous Me2Me host. This button appears on the 'session-finished' page."
   },
+  "RETRY": {
+    "message": "Retry",
+    "description": "Label for button to retry connecting to a Me2Me host, after failing to connect to that host. This button appears on the 'session-finished' page."
+  },
   "SIGN_OUT_BUTTON": {
     "message": "Sign out",
     "description": "Sign out button, visible if the user has authenticated. Clicking this clears authentication credentials and returns the web-app to the initial 'unauthenticated' state."
   },
   "STOP_SHARING_BUTTON": {
     "message": "Stop Sharing",
     "description": "Label for the 'stop sharing' button on the host-side. Clicking this button disconnects the client."
   },
   "TIME_HEADER": {
     "message": "Time",
@@ skipping 23 matching lines @@
   },
   "WARNING_NAT_DISABLED": {
     "message": "NOTE: Policy settings permit connections only between computers within your network.",
     "description": "Message displayed at the bottom of the host screen if local policy dictates that NAT traversal is disabled, meaning that connections outside the local network will not work."
   },
   "YES": {
     "message": "Yes",
     "description": "Label for general-purpose 'Yes' buttons."
   }
 }