fix: susceptable -> susceptible (mdn#20788)

files/en-us/web/api/service_worker_api/index.md

@@ -23,7 +23,7 @@ A service worker is an event-driven [worker](/en-US/docs/Web/API/Worker) registe
 
 A service worker is run in a worker context: it therefore has no DOM access, and runs on a different thread to the main JavaScript that powers your app, so it is non-blocking. It is designed to be fully async; as a consequence, APIs such as synchronous [XHR](/en-US/docs/Web/API/XMLHttpRequest) and [Web Storage](/en-US/docs/Web/API/Web_Storage_API) can't be used inside a service worker.
 
-Service workers only run over HTTPS, for security reasons. Most significantly, HTTP connections are susceptable to malicious code injection by {{Glossary("MitM", "man in the middle")}} attacks, and such attacks could be worse if allowed access to these powerful APIs. In Firefox, service worker APIs are also hidden and cannot be used when the user is in [private browsing mode](https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history).
+Service workers only run over HTTPS, for security reasons. Most significantly, HTTP connections are susceptible to malicious code injection by {{Glossary("MitM", "man in the middle")}} attacks, and such attacks could be worse if allowed access to these powerful APIs. In Firefox, service worker APIs are also hidden and cannot be used when the user is in [private browsing mode](https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history).
 
 > **Note:** On Firefox, for testing you can run service workers over HTTP (insecurely); simply check the **Enable Service Workers over HTTP (when toolbox is open)** option in the Firefox Devtools options/gear menu.