change handling of GLOBAL_ENABLE_LABELS when disabled

backend.php

@@ -2252,6 +2252,8 @@
 	if ($op == "pref-labels") {
 
 		if (!GLOBAL_ENABLE_LABELS) { 
+
+			print "<p>Sorry, labels have been administratively disabled for this installation. Please contact instance owner or edit configuration file to enable this functionality.</p>";
 			return; 
 		}
 

prefs.php

@@ -132,7 +132,7 @@ window.onload = init;
 		<? } ?>
 		<input id="filterConfigTab" class="prefsTab" type="submit" value="Content Filtering"
 			onclick="selectTab('filterConfig')">
-		<? if (GLOBAL_ENABLE_LABELS && get_pref($link, 'ENABLE_LABELS')) { ?>
+		<? if (get_pref($link, 'ENABLE_LABELS')) { ?>
 		<input id="labelConfigTab" class="prefsTab" type="submit" value="Label Editor"
 			onclick="selectTab('labelConfig')">
 		<? } ?>