Fix the IPv6 address and port parsing

There can be lot of possibility for IPv6 address with port,
for example [::1]:80 or [2001:db8:85a3::8a2e:370]:7334.

Parsing that in more standard way is provided by oslo_uilts.netutils
parse_host_port() method[1].

Story: #2006309
Task: #36030

[1] 1b8bafb391/oslo_utils/netutils.py (L37)

Change-Id: Ie7a3bd3074c02430c754deaebfde6d174563b31e

monasca_notification/conf/types.py

@@ -16,6 +16,7 @@ from oslo_config import cfg
 from oslo_config import types
 from oslo_log import log
 from oslo_utils import importutils
+from oslo_utils import netutils
 
 LOG = log.getLogger(__name__)
 
@@ -77,10 +78,11 @@ class HostAddressPortType(types.HostAddress):
                                                   type_name=type_name)
 
     def __call__(self, value):
-        addr, port = value.split(':')
+        addr, port = netutils.parse_host_port(value)
 
         addr = self._validate_addr(addr)
         port = self._validate_port(port)
+        LOG.debug('addr: %s port: %s' % (addr, port))
 
         if addr and port:
             return '%s:%d' % (addr, port)