Run ifconfig as sudo for OSes that require it

Change-Id: I4fbfa5ba90cde1c6d8a608f1883ae3183abf4c6b
diff --git a/tools/test/bin/onos-config b/tools/test/bin/onos-config
index 178bd23..0921c13 100755
--- a/tools/test/bin/onos-config
+++ b/tools/test/bin/onos-config
@@ -31,7 +31,7 @@
     sudo perl -pi -e \"s/        <name>onos</        <name>${ONOS_CELL:-onos}</g\" \
         $ONOS_INSTALL_DIR/$KARAF_DIST/etc/hazelcast.xml
 
-    echo \"onos.ip = \$(ifconfig | grep $ONOS_NIC | cut -d: -f2 | cut -d\\  -f1)\" \
+    echo \"onos.ip = \$(sudo ifconfig | grep $ONOS_NIC | cut -d: -f2 | cut -d\\  -f1)\" \
         >> $ONOS_INSTALL_DIR/$KARAF_DIST/etc/system.properties
 
     # Drop copycat related log level for the console