check whether replica exists before executing the domain level 1 deletion code

Move this check before the parts that check topology suffix connectivity, wait
for removed segments etc. If the hostname does not exist, it should really be
one of the first errors user encounters during ipa-replica-manage del.

https://fedorahosted.org/freeipa/ticket/5424

Reviewed-By: Martin Basti <mbasti@redhat.com>
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>

install/tools/ipa-replica-manage

@@ -668,6 +668,16 @@ def del_master_managed(realm, hostname, options):
         print("Can't remove itself: %s" % (options.host))
         sys.exit(1)
 
+    try:
+        api.Command.server_show(hostname_u)
+    except errors.NotFound:
+        if not options.cleanup:
+            print("{hostname} is not listed among IPA masters.".format(
+                hostname=hostname))
+            print("Please specify an actual server or add the --cleanup "
+                  "option to force clean up.")
+            sys.exit(1)
+
     # 1. Connect to the local server
     try:
         thisrepl = replication.ReplicationManager(realm, options.host,
@@ -702,13 +712,7 @@ def del_master_managed(realm, hostname, options):
     try:
         api.Command.server_del(hostname_u)
     except errors.NotFound:
-        if not options.cleanup:
-            print("{hostname} does not exist.".format(hostname=hostname))
-            print("Please specify an actual server or add the --cleanup "
-                  "option to force clean up.")
-            sys.exit(1)
-        else:
-            print("Server entry already deleted: %s" % (hostname))
+        print("Server entry already deleted: %s" % (hostname))
 
     # 6. Cleanup
     try: