Issue 5750 - Always require subscriptionInit, avoid "critical dependency"

messageResponder.js

Index: messageResponder.js
diff --git a/messageResponder.js b/messageResponder.js
index b9cb74fd5a6dbaaff8437113c15535d9f2c36819..1caa58529d8c2dbf982c431157260fdd5d57c772 100644
--- a/messageResponder.js
+++ b/messageResponder.js
@@ -49,22 +49,6 @@
     return filterTypes;
   });
 
-  // Some modules doesn't exist on Firefox. Moreover,
-  // require() throws an exception on Firefox in that case.
-  // However, try/catch causes the whole function to to be
-  // deoptimized on V8. So we wrap it into another function.
-  function tryRequire(module)
-  {
-    try
-    {
-      return require(module);
-    }
-    catch (e)
-    {
-      return null;
-    }
-  }
-
   function convertObject(keys, obj)
   {
     let result = {};
@@ -166,7 +150,7 @@
   {
     if (message.what == "issues")
     {
-      let subscriptionInit = tryRequire("subscriptionInit");
+      let subscriptionInit = require("subscriptionInit");
       let result = subscriptionInit ? subscriptionInit.reinitialized : false;
       return {filterlistsReinitialized: result};
     }