Handle no network provider

app/src/main/java/org/traccar/client/MixedPositionProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton.tananaev@gmail.com)
+ * Copyright 2015 - 2017 Anton Tananaev (anton.tananaev@gmail.com)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -75,8 +75,12 @@ public class MixedPositionProvider extends PositionProvider implements LocationL
                 }
             };
 
-            locationManager.requestLocationUpdates(
-                    LocationManager.NETWORK_PROVIDER, requestInterval, 0, backupListener);
+            try {
+                locationManager.requestLocationUpdates(
+                        LocationManager.NETWORK_PROVIDER, requestInterval, 0, backupListener);
+            } catch (IllegalArgumentException e) {
+                Log.w(TAG, e);
+            }
         }
     }