[FIX] web_editor: prevent crash when dropping snippets

For some unknown reasons, the editor sometimes crashes when dropping a
snippet. As a temporary fix, the non-critical line that causes the
problem is try/catch protected by this commit.

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

@@ -280,7 +280,15 @@ var RTE = Widget.extend({
         } else {
             rng = $editable.data('range') || rng;
         }
-        rng.select();
+        try {
+            // TODO this line might break for unknown reasons. I suppose that
+            // the created range is an invalid one. As it might be tricky to
+            // adapt that line and that it is not a critical one, temporary fix
+            // is to ignore the errors that this generates.
+            rng.select();
+        } catch (e) {
+            console.log('error', e);
+        }
         history.recordUndo($editable, event, internal_history);
     },
     /**