Bug 1929845 - Fix some typos. r=mkmelin

Depends on D228320

Differential Revision: https://phabricator.services.mozilla.com/D228321

--HG--
extra : moz-landing-system : lando

mail/base/content/about3Pane.js

@@ -4463,7 +4463,7 @@ var threadPane = {
     }
 
     if ((event.key == "Backspace" || event.key == "Delete") && event.repeat) {
-      // Bail on delete event if there is a repeat event to prevent deleteing
+      // Bail on delete event if there is a repeat event to prevent deleting
       // multiple messages by mistake from a longer key press.
       event.preventDefault();
       return;

mail/base/content/mailWindow.js

@@ -1113,7 +1113,7 @@ window.addEventListener("aboutMessageLoaded", event => {
   // eslint-disable-next-line no-shadow
   event.target.document.addEventListener("keypress", event => {
     if ((event.key == "Backspace" || event.key == "Delete") && event.repeat) {
-      // Bail on delete event if there is a repeat event to prevent deleteing
+      // Bail on delete event if there is a repeat event to prevent deleting
       // multiple messages by mistake from a longer key press.
       event.preventDefault();
     }

mail/test/browser/openpgp/browser_viewMessage.js

@@ -265,7 +265,7 @@ add_task(async function testOpenForwardedEncrypted() {
   await BrowserTestUtils.closeWindow(msgc);
 });
 
-// TODO: the above tests that an encrypted .eml can be opnened from an unencrypted message.
+// TODO: the above tests that an encrypted .eml can be opened from an unencrypted message.
 // We should also test/handle:
 //  - other attachment (like .doc) in an encrypted message
 //  - unencrypted .eml attachment in encrypted message (currently broken - bug 1926607)