Fix "Link to account" button in Umbraco 7.5.0-beta / 7.5.0-beta2

~\Umbraco\Views\common\overlays\user\user.html

<form ng-if="login.linkedProviderKey == undefined" method="POST" name="externalLoginForm"
      action="{{externalLinkLoginFormAction}}" id="oauthloginform" name="oauthloginform">
    <input type="hidden" name="provider" value="{{login.authType}}" />
    <button class="btn btn-block btn-social"
            ng-class="login.properties.SocialStyle"
            id="{{login.authType}}"
            onclick="document.forms.oauthloginform.submit();">

        <i class="fa" ng-class="login.properties.SocialIcon"></i>
        <localize key="defaultdialogs_linkYour">Link your</localize> {{login.caption}} <localize key="defaultdialogs_account">account</localize>
    </button>
</form>