fp_useragent: update useragent

marionette/tor_browser_tests/test_fp_useragent.py

@@ -10,5 +10,5 @@ class Test(MarionetteTestCase):
             js = self.marionette.execute_script
             # Check that useragent string is as expected
             # We better know the ESR version we're testing
-            self.assertEqual("Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Firefox/38.0",
+            self.assertEqual("Mozilla/5.0 (Windows NT 6.1; rv:45.0) Gecko/20100101 Firefox/45.0",
                               js("return navigator.userAgent"))