Fix an http test failing due to new static resource URL prefixes.

packages/http/httpcall_tests.js

@@ -485,16 +485,22 @@ if (Meteor.isServer) {
       // the x-suppress-error header).
       WebApp.suppressConnectErrors();
 
-      var do_test = function (path, code, match) {
-        HTTP.get(
-          url_base() + path,
-          {headers: {'x-suppress-error': 'true'}},
-          expect(function(error, result) {
-            test.equal(result.statusCode, code);
-            if (match)
-              test.matches(result.content, match);
-          }));
-      };
+      function do_test(path, code, match) {
+        const prefix = Meteor.isModern
+          ? "/__browser"
+          : "/__browser.legacy";
+
+        HTTP.get(url_base() + prefix + path, {
+          headers: {
+            "x-suppress-error": "true"
+          }
+        }, expect(function(error, result) {
+          test.equal(result.statusCode, code);
+          if (match) {
+            test.matches(result.content, match);
+          }
+        }));
+      }
 
       // existing static file
       do_test("/packages/local-test_http/test_static.serveme", 200, /static file serving/);

packages/modern-browsers/TODO.md

@@ -32,7 +32,7 @@
 
 - [ ] Fix dynamic module source map URLs (prepend `/__arch`).
 
-- [ ] Fix tests failing because of changes to static resource URLs.
+- [x] Fix tests failing because of changes to static resource URLs.
 
 - [ ] In development, save time by only rebuilding `web.browser` (modern)?