fix: correct unreasonable value during test

Change max symbol len from 8 to 12 since that the current
allow value range is 11-33, and 8 will make test fail after we
adding value range constrain into the setting schema file.

test/ibus-chewing-engine-test.c

@@ -88,7 +88,7 @@ gint main(gint argc, gchar **argv) {
     mkdg_log_set_level(DEBUG);
     engine = ibus_chewing_engine_new();
     ibus_chewing_pre_edit_save_property_int(engine->icPreEdit,
-                                            "max-chi-symbol-len", 8);
+                                            "max-chi-symbol-len", 12);
     ibus_chewing_pre_edit_set_apply_property_boolean(engine->icPreEdit,
                                                      "plain-zhuyin", FALSE);