select correct default for ldap uri, selects not php version for compatibility with Ubuntu

manifests/lam.pp

@@ -33,7 +33,7 @@ class wmdeit_ldap::lam(
         }
 
         class { 'apache::mod::php':
-                php_version => '7.3'
+#                php_version => '7.3'
         }
 
         class { '::php':
@@ -126,8 +126,8 @@ class wmdeit_ldap::lam(
 						},
 
 			server_url => $conf['server_url'] ? {
-							undef => "",
-							default => 'ldap://localhost:389'
+							undef => 'ldap://localhost:389',
+							default => $conf['server_url'],
 						},
 		} 
 	}