Notify if Bugzilla is private (#1115)

Although the primary error no longer exist, but the bot shows nothing if
the bugzilla has invalid alias, invaid id or if it has no valid
permission to access the bug. The logs should show warnings such as,

  WARNING:sopel.modules.bugzilla:Bugzilla error: NotFound <- (Invalid ID)
  WARNING:sopel.modules.bugzilla:Bugzilla error: NotPermitted <- (No permission)

This patch should notify about those errors.

Closes-Bug: #1112

Signed-off-by: Sachin Patil <[email protected]>

sopel/modules/bugzilla.py

@@ -70,7 +70,9 @@ def show_bug(bot, trigger, match=None):
     error = bug.get('@error', None)  # error="NotPermitted"
 
     if error:
-        LOGGER.warning('Bugzilla error: %s', error)
+        LOGGER.warning('Bugzilla error: %s' % error)
+        bot.say('[BUGZILLA] Unable to get infomation for '
+                'linked bug (%s)' % error)
         return
 
     message = ('[BUGZILLA] %s | Product: %s | Component: %s | Version: %s | ' +