replica promotion: check domain level before ipaservers membership

Check domain level before checking ipaservers membership to prevent
"not found" error when attempting replica promotion in domain level 0.

https://fedorahosted.org/freeipa/ticket/5401

Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>

ipaserver/install/server/replicainstall.py

@@ -975,6 +975,20 @@ def promote_check(installer):
         replman = ReplicationManager(config.realm_name,
                                      config.master_host_name, None)
 
+        # Detect the current domain level
+        try:
+            current = remote_api.Command['domainlevel_get']()['result']
+        except errors.NotFound:
+            # If we're joining an older master, domain entry is not
+            # available
+            current = constants.DOMAIN_LEVEL_0
+
+        if current == constants.DOMAIN_LEVEL_0:
+            raise RuntimeError(
+                "You must provide a file generated by ipa-replica-prepare to "
+                "create a replica when the domain is at level 0."
+            )
+
         # Check authorization
         result = remote_api.Command['hostgroup_find'](
             cn=u'ipaservers',
@@ -1029,20 +1043,6 @@ def promote_check(installer):
                   config.host_name)
             sys.exit(3)
 
-        # Detect the current domain level
-        try:
-            current = remote_api.Command['domainlevel_get']()['result']
-        except errors.NotFound:
-            # If we're joining an older master, domain entry is not
-            # available
-            current = constants.DOMAIN_LEVEL_0
-
-        if current == constants.DOMAIN_LEVEL_0:
-            raise RuntimeError(
-                "You must provide a file generated by ipa-replica-prepare to "
-                "create a replica when the domain is at level 0."
-            )
-
         # Detect if current level is out of supported range
         # for this IPA version
         under_lower_bound = current < constants.MIN_DOMAIN_LEVEL