If null is unexpected, throw error to more accurately inform player of malformed parameters

src/main/java/me/libraryaddict/disguise/utilities/parser/params/ParamInfo.java

@@ -83,6 +83,11 @@ public abstract class ParamInfo {
 
         Object value = fromString(string);
 
+        // Throw error if null wasn't expected
+        if (value == null && !canReturnNull()) {
+            throw new IllegalArgumentException();
+        }
+
         arguments.remove(0);
 
         return value;