Fixed firefox support.

background.js

@@ -1,3 +1,6 @@
+// Used only on Firefox, which does not support non persistent background pages.
+var contentScriptRegistrations = {};
+
 chrome.tabs.onUpdated.addListener(function(tabId) {
 	chrome.tabs.sendMessage(tabId, {
         message: 'update',
@@ -37,7 +40,22 @@ chrome.runtime.onMessage.addListener(function (request, sender, callback) {
                 message: chrome.i18n.getMessage("leftTimes"),
                 iconUrl: "./icons/LogoSponsorBlocker256px.png"
             });
-	}
+            return false;
+        case "registerContentScript": 
+            browser.contentScripts.register({
+                allFrames: request.allFrames,
+                js: request.js,
+                css: request.css,
+                matches: request.matches
+            }).then(() => void (contentScriptRegistrations[request.id] = registration));
+            
+            return false;
+        case "unregisterContentScript": 
+            contentScriptRegistrations[request.id].unregister();
+            delete contentScriptRegistrations[request.id];
+            
+            return false;
+}
 });
 
 //add help page on install

options/options.js

@@ -2,7 +2,8 @@ window.addEventListener('DOMContentLoaded', init);
 
 var invidiousInstancesRegex = [];
 for (const url of supportedInvidiousInstances) {
-    invidiousInstancesRegex.push("*://*." + url + "/*");
+    invidiousInstancesRegex.push("https://*." + url + "/*");
+    invidiousInstancesRegex.push("http://*." + url + "/*");
 }
 
 async function init() {
@@ -19,6 +20,7 @@ async function init() {
         switch (optionsElements[i].getAttribute("option-type")) {
             case "toggle": 
                 let option = optionsElements[i].getAttribute("sync-option");
+
                 chrome.storage.sync.get([option], function(result) {
                     let optionResult = result[option];
                     let checkbox = optionsElements[i].querySelector("input");
@@ -141,7 +143,9 @@ function invidiousOnClick(checkbox, option) {
                         firefoxCSS.push({file});
                     }
 
-                    let registration = await browser.contentScripts.register({
+                    chrome.runtime.sendMessage({
+                        message: "registerContentScript",
+                        id: "invidious",
                         allFrames: true,
                         js: firefoxJS,
                         css: firefoxCSS,
@@ -178,7 +182,10 @@ function invidiousOnClick(checkbox, option) {
         });
     } else {
         if (isFirefox()) {
-            // Nothing for now
+            chrome.runtime.sendMessage({
+                message: "unregisterContentScript",
+                id: "invidious"
+            });
         } else {
             chrome.declarativeContent.onPageChanged.removeRules(["invidious"]);
         }