[Telemetry] Set facebook_crendentials_backend_2's url to https

tools/telemetry/telemetry/core/backends/facebook_credentials_backend.py

Index: tools/telemetry/telemetry/core/backends/facebook_credentials_backend.py
diff --git a/tools/telemetry/telemetry/core/backends/facebook_credentials_backend.py b/tools/telemetry/telemetry/core/backends/facebook_credentials_backend.py
index 83de295584bb65db5c5e756fa1ed68b870eff62d..a95c4cb6bf876dd540e078212085c76472e3b96c 100644
--- a/tools/telemetry/telemetry/core/backends/facebook_credentials_backend.py
+++ b/tools/telemetry/telemetry/core/backends/facebook_credentials_backend.py
@@ -35,7 +35,12 @@ class FacebookCredentialsBackend(
     return 'pass'
 
 class FacebookCredentialsBackend2(FacebookCredentialsBackend):
+  """ Facebook credential backend for https client. """
 
   @property
   def credentials_type(self):
     return 'facebook2'
+
+  @property
+  def url(self):
+    return 'https://www.facebook.com/'