[FIX] web_editor: prevent crash on outside-iframe click

The editor is performing text selection check when clicking on the
window. However, when clicking outside the iframe an editor is running
in, a crash may occur as the editor was trying to check a range outside
of its environment (the iframe).

Related to opw-1837818

addons/web_editor/static/src/js/rte.summernote.js

@@ -630,7 +630,15 @@ function summernote_mousedown (event) {
     }
 
     // restore range if range lost after clicking on non-editable area
-    var r = range.create();
+    try {
+        var r = range.create();
+    } catch (e) {
+        // If this code is running inside an iframe-editor and that the range
+        // is outside of this iframe, this will fail as the iframe does not have
+        // the permission to check the outside content this way. In that case,
+        // we simply ignore the exception as it is as if there was no range.
+        return;
+    }
     var editables = $(".o_editable[contenteditable], .note-editable[contenteditable]");
     var r_editable = editables.has((r||{}).sc);
     if (!r_editable.closest('.note-editor').is($editable) && !r_editable.filter('.o_editable').is(editables)) {