[setSignText] Fix ClassCastException

Author: sandtechnology

src/main/java/org/maxgamer/quickshop/shop/ContainerShop.java

@@ -878,7 +878,7 @@ public void setSignText(@NotNull List<ComponentPackage> lines) {
                     //Due to spigot internal changes, snapshot need to be updated for nbt changes
                     //Such thing not happened to paper (we disable snapshot when getting state),
                     //for performance improvement, we use paperlib to skip snapshot creating again
-                    sign = (Sign) PaperLib.getBlockState(sign.getBlock(), false);
+                    sign = (Sign) PaperLib.getBlockState(sign.getBlock(), false).getState();
                 } catch (Exception e) {
                     plugin.getLogger().log(Level.WARNING, "NBTAPI support is broken, disable and fallback... (You can safely ignore this)", e);
                     plugin.disableNBTAPI();