Fixed error if no geo location backend is selected.

app/models/user_device.rb

@@ -23,7 +23,10 @@ store device for user
 
     # get location info
     location_details = Service::GeoIp.location(ip)
+    location = 'unknown'
+    if location_details
       location = location_details['country_name']
+    end
 
     # find device by fingerprint
     if fingerprint

lib/application_lib.rb

@@ -20,6 +20,7 @@ returns
     def load_adapter_by_setting(setting)
       adapter = Setting.get(setting)
       return if !adapter
+      return if adapter.empty?
 
       # load backend
       load_adapter(adapter)