Fix Learn More link for printer settings

- Fixes a regression where the learn more link was referencing a bad
  URL.

Bug: 1038646
Test: local
Change-Id: I010531e4749c8421963c98107ea0305657192913
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2146061
Commit-Queue: jimmy gong <jimmyxgong@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Auto-Submit: jimmy gong <jimmyxgong@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758372}

chrome/browser/resources/settings/chromeos/os_printing_page/cups_printers.html

@@ -121,7 +121,7 @@
       </div>
       <settings-localized-link class="secondary"
           localized-string="$i18n{nearbyPrintersListDescription}"
-          link-url="$i18n{nearbyPrintersListDescription}">
+          link-url="$i18n{printingCUPSPrintLearnMoreUrl}">
       </settings-localized-link>
       <template is="dom-if" if="[[!addPrinterButtonActive_(canAddPrinter,
           prefs.native_printing.user_native_printers_allowed.value)]]">