fixes to catch proper netconf exception

- part of ONOS-7020

Change-Id: I55c02ca9fdb97f1ae12b4e3d7b76da565f9da741
diff --git a/drivers/microsemi/src/main/java/org/onosproject/drivers/microsemi/NetconfConfigGetter.java b/drivers/microsemi/src/main/java/org/onosproject/drivers/microsemi/NetconfConfigGetter.java
index 087af0c..039b760 100644
--- a/drivers/microsemi/src/main/java/org/onosproject/drivers/microsemi/NetconfConfigGetter.java
+++ b/drivers/microsemi/src/main/java/org/onosproject/drivers/microsemi/NetconfConfigGetter.java
@@ -19,8 +19,6 @@
 import static org.onosproject.netconf.DatastoreId.datastore;
 import static org.slf4j.LoggerFactory.getLogger;
 
-import java.io.IOException;
-
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.onosproject.net.DeviceId;
@@ -30,6 +28,7 @@
 import org.onosproject.net.packet.PacketProcessor;
 import org.onosproject.net.packet.PacketService;
 import org.onosproject.netconf.NetconfController;
+import org.onosproject.netconf.NetconfException;
 import org.slf4j.Logger;
 
 import com.google.common.base.Preconditions;
@@ -69,7 +68,7 @@
         try {
             return controller.getDevicesMap().get(ofDeviceId).getSession()
                     .getConfig(datastore(type.replace("cfgType=", "")));
-        } catch (IOException e) {
+        } catch (NetconfException e) {
             log.error("Configuration could not be retrieved {}", e.getMessage());
         }
         return UNABLE_TO_READ_CONFIG;