UWMOODLE-675: UW My Courses block revealing webservice tokens

Task-Url: https://jira.doit.wisc.edu/jira/browse/UWMOODLE-675

getcourses.php

@@ -55,7 +55,7 @@ if(confirm_sesskey()) {
     list($courses, $errors) = block_course_overview_uwmoodle_get_sorted_courses();
 
     if(!empty($errors)){
-        if(debugging()){
+        if(debugging() && is_siteadmin()){
             $response->errors = $errors;
         }else{
             $response->errors = get_string('general_warning_message', 'block_course_overview_uwmoodle');

renderer.php

@@ -346,7 +346,7 @@ class block_course_overview_uwmoodle_renderer extends plugin_renderer_base {
                     error_log($error);
                 }
 
-                if(debugging()){ // if debugging show actual error messages
+                if(debugging() && is_siteadmin()){ // if debugging show actual error messages
 
                     $output .= html_writer::alist($errors);