do not allow to create receipt if there is already one

pass/public/styles/base.less

@@ -123,7 +123,8 @@ button {
     border-color: fade(darken(@color-secondary, 5%), 70%);
     color: fade(white, 90%);
   }
-  &.disabled {
+  &.disabled,
+  &[disabled] {
     background-color: fade(@color-secondary, 30%);
     border-color: fade(darken(@color-secondary, 5%), 30%);
     color: @font-color-on-white;

pass/routes/admin/index.js

@@ -113,7 +113,7 @@ router.post("/payments/receipt",
       url.searchParams.append("name", reqData.name)
     }
 
-    if (!data_complete) {
+    if (!data_complete || reqData.order.isReceiptCreated()) {
       res.redirect(url.toString());
       return;
     }

pass/views/admin/payments/receipt.ejs

@@ -55,7 +55,7 @@
         <label for="address"><%= req.t("receipt.address.label", {ns: "admin"}) _%></label>
         <textarea name="address" id="address" cols="30" rows="3" placeholder="Mustergasse 3&#10;30159 Musterstadt&#10;Deutschland"><%= typeof address === "undefined" ? "" : address _%></textarea>
       </div>
-      <button class="button"><%= req.t("receipt.submit-userdata", {ns: "admin"}) _%></button>
+      <button class="button" <%_ if(order.isReceiptCreated()) { _%>disabled<%_ }_%>><%= req.t("receipt.submit-userdata", {ns: "admin"}) _%></button>
     </form>
     <%_ } _%>
   </div>