Minor adjustments / bug fixes

- restrict extension to secure context (HHTPS),
  since "setSinkId()" requires this anyway
- avoid error when popup is opened for a Tab with a null URL

extension/manifest.json

@@ -33,19 +33,19 @@
 		"96": "AP_Icon96.png",
 		"128": "AP_Icon128.png"
 	},
-	"host_permissions": ["<all_urls>"],
+	"host_permissions": ["https://*/*"],
 	"background": {
 		"service_worker": "worker.js"
 	},
 	"content_scripts": [
 		{
-			"matches": ["<all_urls>"],
+			"matches": ["https://*/*"],
 			"js": ["content.js"],
 			"world": "ISOLATED",
 			"all_frames" : true
 		},
 		{
-			"matches": ["<all_urls>"],
+			"matches": ["https://*/*"],
 			"js": ["main.js"],
 			"world": "MAIN",
 			"all_frames" : true

extension/popup.js

@@ -183,7 +183,7 @@ async function init() {
 	});
 	// If we're not on http or https immediately close.
 	// Extension doesn't like to work on chrome:// or file:// URLs.
-	if (activeTab.url.toLowerCase().indexOf("http") === -1) {
+	if (!activeTab.url || (activeTab.url.toLowerCase().indexOf("https") === -1)) {
 		window.close();
 		return;
 	}