Fix batch enrollment box email sending

lms/static/coffee/src/instructor_dashboard/membership.coffee

@@ -180,7 +180,7 @@ class BetaTesterBulkAddition
     # gather elements
     @$emails_input           = @$container.find("textarea[name='student-emails-for-beta']")
     @$btn_beta_testers       = @$container.find("input[name='beta-testers']")
-    @$checkbox_emailstudents = @$container.find("input[name='email-students']")
+    @$checkbox_emailstudents = @$container.find("input[name='email-students-beta']")
     @$task_response          = @$container.find(".request-response")
     @$request_response_error = @$container.find(".request-response-error")
 
@@ -268,7 +268,7 @@ class BatchEnrollment
 
     # attach click handler for enrollment buttons
     @$enrollment_button.click =>
-      emailStudents: @$checkbox_emailstudents.is(':checked')
+      emailStudents = @$checkbox_emailstudents.is(':checked')
       send_data =
         action: $(event.target).data('action') # 'enroll' or 'unenroll'
         emails: @$emails_input.val()

lms/templates/instructor/instructor_dashboard_2/membership.html

@@ -81,7 +81,7 @@
   </p>
 
   <div class="enroll-option">
-    <input type="checkbox" name="email-students" value="Notify-students-by-email" checked="yes">
+    <input type="checkbox" name="email-students-beta" value="Notify-students-by-email" checked="yes">
     <label for="email-students-beta">${_("Notify users by email")}</label>
     <div class="hint email-students-beta-hint">
       <span class="hint-caret"></span>