senml: Fix data record encoding to use binascii instead of base64.

micropython/senml/senml/senml_record.py

@@ -190,7 +190,9 @@ class SenmlRecord(SenmlBase):
             if (
                 naming_map["vd"] == "vd"
             ):  # neeed to make a distinction between json (needs base64) and cbor (needs binary)
-                result[naming_map["vd"]] = base64.b64encode(self._value)
+                result[naming_map["vd"]] = binascii.b2a_base64(self._value, newline=False).decode(
+                    "utf8"
+                )
             else:
                 result[naming_map["vd"]] = self._value
         else: