Fix a typo in the executables download page.
<tr>
<td>Linux - x86_64 64 bit<br />
Fedora 31, 4.19.76-linuxkit #1 SMP, gcc 9.3.1</td>
- <td><a href="https://github.com/visit-dav/visit/releases/download/v3.1.3/visit3_1_3.linux-x86_64-fedora27.tar.gz">Download</a></td>
+ <td><a href="https://github.com/visit-dav/visit/releases/download/v3.1.3/visit3_1_3.linux-x86_64-fedora31.tar.gz">Download</a></td>
</tr>
<tr>
<td>Linux - x86_64 64 bit<br />
