conman:  Minor cleanup.

A recent commit removed the temporary metric 99 routes used for
connection checks.  This removes a spurious remaining reference to
them.

Change-Id: Iedf94d04ca5ed80700fc141dfcb9136dd13b3a3b
diff --git a/conman/connection_manager.py b/conman/connection_manager.py
index d530639..fd2bcc8 100755
--- a/conman/connection_manager.py
+++ b/conman/connection_manager.py
@@ -589,9 +589,6 @@
       route = ifc.current_routes().get('default', None)
       if route:
         metric = route.get('metric', 0)
-        # Skip temporary connection_check routes.
-        if metric == '99':
-          continue
         candidate = (metric, ifc)
         if (lowest_metric_interface is None or
             candidate < lowest_metric_interface):