Don't activate Many2One on TAB key if completion is active

otherwise when selection the completion, a search pop-up is raised.

src/view.js

@@ -3167,6 +3167,12 @@
                 this.edit();
                 event_.preventDefault();
             } else if (~activate_keys.indexOf(event_.which) && editable) {
+                if (!this.attributes.completion ||
+                        this.attributes.completion == "1") {
+                    if (this.el.find('.dropdown').hasClass('open')) {
+                        return;
+                    }
+                }
                 this.activate();
             } else if (this.has_target(this.record().field_get(
                             this.field_name)) && editable) {