dont async handle massinput if from outside massinput element

static/js/utils/massInput.js

@@ -65,6 +65,13 @@
       }
 
       return function(event) {
+        // check if event occured from either a mass input add/delete button or
+        // from inside one of massinput's inputs (i.e. they are focused/active)
+        var activeElement = element.querySelector(':focus, :active');
+        if (!activeElement) {
+          return false;
+        }
+
         event.preventDefault();
         var formData = new FormData(massInputForm);
 
@@ -83,7 +90,6 @@
             {
               'Content-Type': enctype,
               'Mass-Input-Shortcircuit': massInputId,
-              'Upgrade-Insecure-Requests': 1,
             },
             requestBody,
           ).then(function(response) {