fix: open translation correctly from the options page

When trying to show a translation in a new tab after selecting text in
the options page and clicking the "Translate selection" context menu
item, the extension didn't open the tab at all.

This CL fixes this issue by not passing an openerTabId when it isn't
available.

Fixed: translateselectedtext:22
Change-Id: I255073cba84bd574d2296468dc21736071f5e821
diff --git a/src/background.ts b/src/background.ts
index 2db72b9..02dd05a 100644
--- a/src/background.ts
+++ b/src/background.ts
@@ -71,10 +71,9 @@
 
         const url = URLFactory.getTranslationURL(
             contextMenuItem?.language, info, contextMenuItem?.dataType);
-        const newTabOptions: Parameters<typeof chrome.tabs.create>[0] = {
-          url,
-          openerTabId: initiatorTab.id,
-        };
+        const newTabOptions: Parameters<typeof chrome.tabs.create>[0] = {url};
+
+        if (initiatorTab.id > 0) newTabOptions.openerTabId = initiatorTab.id;
         if (initiatorTab.index) newTabOptions.index = initiatorTab.index + 1;
 
         if (contextMenuItem?.dataType !== DataType.DataTypeText) {