fix(CouponCodeInput): mobile buttons adjusted

Related: quiqqer/template-cologne#103

(cherry picked from commit fe49e667)

bin/frontend/controls/CouponCodeInput.css

-.quiqqer-coupons-field {
-    float: left;
-}
-
 div + .quiqqer-coupons-field {
     margin-left: 20px;
 }