removes unused parameter

Author: Fede A

javaobj/v2/core.py

@@ -302,7 +302,7 @@ def _read_content(self, type_code, block_data, class_desc=None):
             except ExceptionRead as ex:
                 return ex.exception_object
 
-    def _read_new_string(self, type_code, field_name=None):
+    def _read_new_string(self, type_code):
         # type: (int) -> JavaString
         """
         Reads a Java String