Add ipsec-site-connections to resource map of a network client

Lines #68 and #71, #97 and #99 are identical.
The removes duplicated lines and it adds ipsec-site-connections
resource. The resource is needed to make NetworkClientJSON work
with ipsec-site-connections. For example tests for ipsec-site-connections
will use it.

Change-Id: I606a5c62ba932ac0f7e6d3cf825e9c5440ffa0d8
diff --git a/tempest/services/network/json/network_client.py b/tempest/services/network/json/network_client.py
index 8602513..daf7101 100644
--- a/tempest/services/network/json/network_client.py
+++ b/tempest/services/network/json/network_client.py
@@ -68,7 +68,7 @@
             'ipsecpolicies': 'vpn',
             'vpnservices': 'vpn',
             'ikepolicies': 'vpn',
-            'ipsecpolicies': 'vpn',
+            'ipsec-site-connections': 'vpn',
             'metering_labels': 'metering',
             'metering_label_rules': 'metering',
             'firewall_rules': 'fw',
@@ -96,7 +96,7 @@
             'security_group_rules': 'security_group_rules',
             'ipsecpolicy': 'ipsecpolicies',
             'ikepolicy': 'ikepolicies',
-            'ipsecpolicy': 'ipsecpolicies',
+            'ipsec_site_connection': 'ipsec-site-connections',
             'quotas': 'quotas',
             'firewall_policy': 'firewall_policies'
         }