Disable useless warnings from nosetests execution

Change-Id: I324bd5fa5b4a552702abe90afd98019791da803a
diff --git a/src/test/utils/SSHTestAgent.py b/src/test/utils/SSHTestAgent.py
index 82f20ad..1f6a6d0 100644
--- a/src/test/utils/SSHTestAgent.py
+++ b/src/test/utils/SSHTestAgent.py
@@ -19,7 +19,7 @@
 
     def run_cmd(self, cmd, timeout = 5):
         """Run the command on the test host"""
-        host_remove = 'ssh-keygen -f "%s" -R [%s]:8101' %(self.hosts_file, self.host)
+        host_remove = 'ssh-keygen -f "%s" -R [%s]:8101 2>/dev/null' %(self.hosts_file, self.host)
         try:
             os.system(host_remove)
         except: pass
@@ -30,7 +30,7 @@
         except:
             log.error('Unable to connect to test host %s' %self.host)
             return False, None
-        
+
         channel = self.client.get_transport().open_session()
         channel.exec_command(cmd)
         if channel.exit_status_ready():