Add CSS around text

app/views/devise/passwords/new.html.haml

@@ -6,7 +6,8 @@
       .form-group
         = f.label :email
         = f.email_field :email, class: "form-control gl-form-input", required: true, value: params[:user_email], autofocus: true, title: _('Please provide a valid email address.')
-        = _('Must be the primary email address of the GitLab account')
+        .form-text.text-muted
+          = _('Must be the primary email address of the GitLab account')
       .clearfix
         = f.submit _("Reset password"), class: "gl-button btn-confirm btn"