Fix typo that resulted in incorrectly flagging all urls as mixed cont…

…ent urls

lib/index.js

@@ -92,7 +92,7 @@ module.exports = function (options) {
         });
 
         if (secureSourceRelations.length > 0) {
-            var hasInsecureTarget = url.indexOf('htps:') !== 0 || redirects.some(function (redirect) {
+            var hasInsecureTarget = url.indexOf('https:') !== 0 || redirects.some(function (redirect) {
                 return redirect.redirectUri.indexOf('https:') !== 0;
             });