Resolve L2SS-247 "2021 07 06 branched from master attribute testing"

Closes L2SS-247

devices/clients/attribute_wrapper.py

@@ -39,7 +39,7 @@ class attribute_wrapper(attribute):
 
 		# tango doesn't recognise numpy.str_, for consistencies sake we convert it here and hide this from the top level
 		# NOTE: discuss, idk if this is an important detail somewhere else
-		if datatype is numpy.str_:
+		if datatype is numpy.str_ or datatype is numpy.str:
 			datatype = str
 
 		self.numpy_type = datatype  # tango changes our attribute to their representation (E.g numpy.int64 becomes "DevLong64")