localhost.localdomain clients refused to join

Machines with hostname 'localhost' or 'localhost.localdomain' are
refused from joining IPA domain and proper error message is shown.
The hostname check is done both in 'ipa-client-install' script and in
'ipa-join'.

https://fedorahosted.org/freeipa/ticket/2112

ipa-client/ipa-install/ipa-client-install

@@ -872,6 +872,9 @@ def install(options, env, fstore, statestore):
     if hostname != hostname.lower():
         print 'Invalid hostname \'%s\', must be lower-case.' % hostname
         return CLIENT_INSTALL_ERROR
+    if (hostname == 'localhost') or (hostname == 'localhost.localdomain'):
+        print 'Invalid hostname, \'%s\' must not be used.' % hostname
+        return CLIENT_INSTALL_ERROR
 
     # when installing with '--no-sssd' option, check whether nss-ldap is installed
     if not options.sssd: