Changed argument from Device -> DeviceId

- roleChanged(), isReachable()
   Eventually consistent nature of Device store was
  interfering with mastership control.

Change-Id: I9c0dd846a4e30863f922f6706c6cb62fd7c83f29
diff --git a/web/api/src/main/java/org/onlab/onos/rest/ConfigProvider.java b/web/api/src/main/java/org/onlab/onos/rest/ConfigProvider.java
index 57e247f..e4a0763 100644
--- a/web/api/src/main/java/org/onlab/onos/rest/ConfigProvider.java
+++ b/web/api/src/main/java/org/onlab/onos/rest/ConfigProvider.java
@@ -244,7 +244,7 @@
     }
 
     @Override
-    public void roleChanged(Device device, MastershipRole newRole) {
+    public void roleChanged(DeviceId device, MastershipRole newRole) {
     }
 
     @Override
@@ -257,7 +257,7 @@
     }
 
     @Override
-    public boolean isReachable(Device device) {
+    public boolean isReachable(DeviceId device) {
         return false;
     }
 }