Quicksearch doesn't work for double byte characters such as Chinese

Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. Install JIRA 7.x or 8.x
2. Create a project and a few issues with "生产问题" or variations as a summary
3. In the quick search box on the top right, try to search for "生产问题" string

Expected Results

Jira should display the list of issues in the quick search results

Actual Results

'No results' is displayed

Workaround

Ignore the 'no results' and hit 'Enter' - JIRA will display the issues