skip groups-related bits when TabView doesn't exist

Author: Quicksaver

common/content/buffer.js

@@ -1445,7 +1445,7 @@ const Buffer = Module("buffer", {
                 context.completions = [item for (item in generateTabs(tabs || config.tabbrowser.visibleTabs))];
             }
 
-            if (!liberator.has("tabgroup"))
+            if (!liberator.has("tabgroup") || !tabGroup.TV)
                 return;
 
             let groups = tabGroup.tabView.GroupItems;

common/content/tabs.js

@@ -406,7 +406,7 @@ const Tabs = Module("tabs", {
         let matches = buffer.match(/^(\d+):?/);
         if (matches)
             return [tabs.getTab(parseInt(matches[1], 10) - 1)];
-        else if (liberator.has("tabgroup")) {
+        else if (liberator.has("tabgroup") && tabGroup.TV) {
             matches = buffer.match(/^(.+?)\.(\d+):?/);
             if (matches) {
                 let [, groupName, tabNum] = matches;