made ItemBaseWirelessTerminal.canHandle null-safe (#274)

Co-authored-by: Maya <10861407+serenibyss@users.noreply.github.com>

src/main/java/com/glodblock/github/common/item/ItemBaseWirelessTerminal.java

@@ -112,6 +112,9 @@ public class ItemBaseWirelessTerminal extends ToolWirelessTerminal implements II
 
     @Override
     public boolean canHandle(final ItemStack is) {
+        if (is == null) {
+            return false;
+        }
         return is.getItem() instanceof ItemBaseWirelessTerminal;
     }