Bold and italics highlighting when there is a space before closing *

**Describe the bug**
When there is a space before the closing * of a part of the text, it shouldn't be italics/bold. In the editor, it not only is higlighted as bold, but the bolding doesn't end with the closing * and continues on.

**To Reproduce**
Steps to reproduce the behavior:
1. Type `**Hello ** World`

**Expected behavior**
\*\*Hello \*\* World

**Actual behaviour**
**\*\*Hello \*\* World**

** Version information **
- OS: Debian testing
- Browser: Firefox, Chrome
- EasyMDE version: 2.5.1