update shu electronics serial num

geomagio/Metadata.py

@@ -496,7 +496,7 @@ _INSTRUMENT_METADATA = [
             },
             # this info should get updated when available
             "electronics": {
-                "serial": "E558",
+                "serial": "E566",
                 # these scale values are used to convert voltage
                 # these are calculated using Ohm's law, given scaling resistor value (38.3 kohm), and given nT/mA values.
                 "x-scale": 944.935,  # nT/V