register: Spell Greek Ακμή with Greek alpha, not Latin A

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

templates/zerver/register.html

@@ -26,7 +26,7 @@ Form is validated both client-side using jquery-validate (see signup.js) and ser
                 <div class="input-box">
                     <div class="inline-block relative">
                         <input id="id_team_name" class="required" type="text"
-                          placeholder="Acme or Aκμή"
+                          placeholder="Acme or Ακμή"
                           value="{% if form.realm_name.value() %}{{ form.realm_name.value() }}{% endif %}"
                           name="realm_name" maxlength={{ MAX_REALM_NAME_LENGTH }} required />
                     </div>

tools/linter_lib/custom_check.py

@@ -604,7 +604,7 @@ html_rules = whitespace_rules + prose_style_rules + [
     {'pattern': r'placeholder="[^{#](?:(?!\.com).)+$',
      'description': "`placeholder` value should be translatable.",
      'exclude_line': {('templates/zerver/register.html', 'placeholder="acme"'),
-                      ('templates/zerver/register.html', 'placeholder="Acme or Aκμή"')},
+                      ('templates/zerver/register.html', 'placeholder="Acme or Ακμή"')},
      'exclude': set(["templates/analytics/support.html"]),
      'good_lines': ['<input class="stream-list-filter" type="text" placeholder="{{ _(\'Search streams\') }}" />'],
      'bad_lines': ['<input placeholder="foo">']},