[FIX] web_editor: correct check of property 'rules'

Port of PR #22603 from v9 to v10
See Issue #22517

 (#22679)

addons/web_editor/static/src/js/transcoder.js

@@ -9,7 +9,7 @@ var getMatchedCSSRules = function (a) {
         var sheets = document.styleSheets;
         for(var i = sheets.length-1; i >= 0 ; i--) {
             var rules;
-            if (sheets[i].rules) {
+            if (sheets[i].hasOwnProperty('rules')) {
                 rules = sheets[i].rules;
             } else {
                 //try...catch because Firefox not able to enumerate document.styleSheets[].cssRules[] for cross-domain stylesheets.

doc/cla/individual/remi-filament.md

@@ -8,4 +8,4 @@ declaration.
 
 Signed,
 
-Rémi CAZENAVE remi@le-filament.com https://github.com/remi-filament
+Rémi CAZENAVE 30716308+remi-filament@users.noreply.github.com https://github.com/remi-filament