Bug 1553029 - Update WebIDE deprecation message to stop mentioning release 69 r=flod,daisuke

There was a last minute schedule change for remote debugging release and we will not ride the trains with Firefox 68
The deprecation schedule is therefore shifting by one release. We update the deprecation message in WebIDE here and we should
uplift this change to beta if possible. The patch was written in order to be uplifted, we can go for a simpler version if the
uplift is a no go.

Differential Revision: https://phabricator.services.mozilla.com/D31970

--HG--
extra : moz-landing-system : lando

devtools/client/locales/en-US/webide.properties

@@ -60,8 +60,8 @@ error_runtimeVersionTooOld=The connected runtime has an old version (%1$S). The
 # Variable: runtime app version (looks like this 52.a3)
 error_runtimeVersionTooOld67Debugger=The Debugger panel may not work with the connected runtime. Please use Firefox %S if you need to use the Debugger with this runtime.
 
-# LOCALIZATION NOTE (error_webIDEDeprecated): Text for the deprecation message displayed when starting WebIDE.
-error_webIDEDeprecated=WebIDE will be disabled in release 69. Remote debugging is now available in about:debugging.
+# LOCALIZATION NOTE (error_webIDEDeprecated2): Text for the deprecation message displayed when starting WebIDE.
+error_webIDEDeprecated2=WebIDE will be disabled in an upcoming release. Remote debugging is now available in about:debugging.
 
 # LOCALIZATION NOTE (notification_openAboutDebugging): Text for a button displayed in the deprecation message for WebIDE.
 # Clicking on the button will open a tab on about:debugging.

devtools/client/webide/content/webide.js

@@ -318,7 +318,15 @@ var UI = {
   },
 
   showDeprecationMessage: function() {
-    const text = Strings.GetStringFromName("error_webIDEDeprecated");
+    let text;
+    try {
+      text = Strings.GetStringFromName("error_webIDEDeprecated2");
+    } catch (e) {
+      // The string error_webIDEDeprecated2 should be upflited to Beta 68. In this
+      // situation, some language packs might not be updated and provide the new string
+      // immediately. Fallback to the previous string in this case.
+      text = Strings.GetStringFromName("error_webIDEDeprecated");
+    }
     const buttons = [{
       label: Strings.GetStringFromName("notification_openAboutDebugging.label"),
       accessKey: Strings.GetStringFromName("notification_openAboutDebugging.accesskey"),