Changed Reset Strategy for set_reset_strategy to open_required (#163

)

Where a micro allows the reset pin to be re-assigned, the reset strategy may
need to be changed prior to establishing a connection. This patch changes the
decorator on the `set_reset_strategy()` method to `open_required()` from
`connection_required()` to allow that to be possible.

pylink/jlink.py

@@ -1961,7 +1961,7 @@ def set_etm_trace(self):
         """
         return self.set_trace_source(enums.JLinkTraceSource.ETM)
 
-    @connection_required
+    @open_required
     def set_reset_strategy(self, strategy):
         """Sets the reset strategy for the target.