Plugin Directory: Blank value for localization suggestion

[terriann]

When searching for a plugin in the plugin directory I am getting the localization suggestion banner (locale banner) with no name for the suggestion.

Banner text: "The plugin directory is also available in"
Link: ​https://wordpress.org/plugins/search/debug+bar/

I saw this banner both when logged in and logged out in an incognito window w/ no plugins installed.

Inspecting the HTML there is a link present but no text in the tag:

<div class="locale-banner">The plugin directory is also available in <a href="https://la.wordpress.org/plugins/search/debug+bar/"></a>.</div>

The source code shows the suggestion is based on headers passed in the request and on that page request I'm passing these headers:

:authority:wordpress.org
:method:GET
:path:/plugins/search/debug+bar/
:scheme:https
accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
accept-encoding:gzip, deflate, br
accept-language:en-US,en;q=0.9,la;q=0.8

I guess it's trying to suggest a Latin site but it's not displaying correctly.

Browser: Chrome Version 63.0.3239.132 (Official Build) (64-bit)
OS: MacOS High Sierra 10.13.2 (17C88)

[terriann]

Screenshot of banner

[SergeyBiryukov]

Previously: #2618

[obenland]

Let's consolidate this with #2517.