conman: Stop noisy logging of wpa_supplicant state.

This log message was useful, but ultimately too noisy, regularly
causing logos throttling to occur.  It might be worth revisiting a
less noisy way of logging this later, but for now, apply the quick fix
to prevent other important log messages from getting dropped.

Change-Id: Id11046d8aaf8fdb554b320551f46b82d1fc897ae
diff --git a/conman/interface.py b/conman/interface.py
index 1de5a59..245ca27 100755
--- a/conman/interface.py
+++ b/conman/interface.py
@@ -459,7 +459,6 @@
       k, v = line.strip().split('=', 1)
       status[k] = v
 
-    self.logger.debug('wpa_status is %r', status)
     return status
 
   def update(self):