admin: hide scrollbar on navbar on chrome

changed overflow-x-scroll to overflow-x-auto, so scrollbar only shows
when needed on chrome. Doesn't occur on firefox or webkit (epiphany), so
didn't notice until I saw others' screenshots.

html/admin.html

@@ -574,7 +574,7 @@
                 </div>
             </div>
             <header>
-                <div class="flex flex-row overflow-x-scroll items-center gap-2">
+                <div class="flex flex-row overflow-x-auto items-center gap-2">
                     <span id="button-tab-invites"  class="text-3xl button portal ~neutral dark:~d_neutral @low px-5">{{ .strings.invites }}</span>
                     <span id="button-tab-accounts" class="text-3xl button portal ~neutral dark:~d_neutral @low px-5">{{ .strings.accounts }}</span>
                     <span id="button-tab-activity" class="text-3xl button portal ~neutral dark:~d_neutral @low px-5">{{ .strings.activity }}</span>