Update login submit row style

jet/static/jet/css/_login.scss

@@ -47,6 +47,11 @@
       height: 100%;
       padding: 30px;
     }
+
+    &-submit-row {
+      text-align: center;
+      margin-top: 20px;
+    }
   }
 }
 

jet/static/jet/css/themes/default/base.css

@@ -4269,6 +4269,9 @@ table#change-history {
       background: #fff;
       height: 100%;
       padding: 30px; }
+    .login-container-submit-row {
+      text-align: center;
+      margin-top: 20px; }
 
 .login-form .form-row {
   padding: 6px 0; }

jet/static/jet/css/themes/green/base.css

@@ -4300,6 +4300,9 @@ table#change-history {
       background: white;
       height: 100%;
       padding: 30px; }
+    .login-container-submit-row {
+      text-align: center;
+      margin-top: 20px; }
 
 .login-form .form-row {
   padding: 6px 0; }

jet/templates/admin/login.html

@@ -50,7 +50,7 @@
                     <a href="{{ password_reset_url }}">{% trans 'Forgotten your password or username?' %}</a>
                     </div>
                 {% endif %}
-                <div class="submit-row">
+                <div class="login-container-submit-row">
                 <label>&nbsp;</label><input type="submit" value="{% trans 'Log in' %}" />
                 </div>
             </form>