Quick typo fix

Author: nloadholtes

views/extension/index.pug

@@ -40,7 +40,7 @@ block content
               | Supported by &nbsp
               img(src="/img/ico_logo.svg")
             a &nbsp-&nbsp
-            a.keep-deco(href='https://github.com/jsonwebtoken/jsonwebtoken.github.io/blob/master/LICENSE.txt', target="_blank") Licence
+            a.keep-deco(href='https://github.com/jsonwebtoken/jsonwebtoken.github.io/blob/master/LICENSE.txt', target="_blank") License
 
           .pull-right.save-back.hide
             a#save-back-link(href="#") Save back to localStorage