Bug 1952856 - Deal with text fragments disabled for now. r=jjaschke

I don't think this is worth a test tbh. We can remove the null-check
when we remove the pref.

Differential Revision: https://phabricator.services.mozilla.com/D241359

browser/actors/ContextMenuChild.sys.mjs

@@ -920,7 +920,7 @@ export class ContextMenuChild extends JSWindowActorChild {
     context.onVideo = false;
     context.inPDFEditor = false;
     context.hasTextFragments =
-      !!this.contentWindow?.document?.fragmentDirective.getTextDirectiveRanges()
+      !!this.contentWindow?.document?.fragmentDirective?.getTextDirectiveRanges()
         .length;
 
     // Remember the node and its owner document that was clicked