Adding a closing parenthesis to "Display remote avatars" help file.

It's better for us to add a closing parenthesis to the Gravatar serve additional URL information.

File to modify:
lang/en.utf8/help/forms/siteoptions.remoteavatars.html

Line:
10

[ Before ]
This option requires both the person and the web server to have access to the Gravatar server (https://gravatar.com. In installations such as locked-down intranets, where such access is not available, enabling this option would simply add extra delays.

[ After ]
This option requires both the person and the web server to have access to the Gravatar server (https://gravatar.com). In installations such as locked-down intranets, where such access is not available, enabling this option would simply add extra delays.