Comment 4 for bug 1829947

It fix my problem. thanks.
the step to reproduce was like this.
1. add ibus-libpinyin as a input method
2. open a text editor
3. choose the ibus-libpinyin as input method
4. type some chinese words.
5. press + or - to select next page , previous page
6. select the right words, pop them to text editor
7. press + or - to try type these symbols(+, -)
8. you can not type them, because the ibus-libpinyin not allow that