[Passwords] Remove unused Compromised Passwords String

This change removes IDS_SETTINGS_LEAKED_PASSWORDS_COUNT, which was
initially removed in r748277, but then accidentally re-added in r748728.
There are no usages of this string, and thus it can safely be removed.

Bug: 1047726
Change-Id: Ib765f74ad8a031cb45cbf229c7031e2a7d39682d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2107484
Auto-Submit: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751098}

chrome/app/settings_strings.grdp

@@ -362,9 +362,6 @@
       =1 {{COUNT} compromised password}
       other {{COUNT} compromised passwords}}
   </message>
-  <message name="IDS_SETTINGS_LEAKED_PASSWORDS_COUNT" desc="Number of compromised passwords found during bulk check.">
-    <ph name="COUNT">$1<ex>5</ex></ph> compromised passwords
-  </message>
   <message name="IDS_SETTINGS_CHECK_PASSWORDS_AGAIN" desc="Button to start bulk password check manually in passwords check section.">
     Check again
   </message>