Fix regression where power_switch does not work with Python backend

This was introduced in 730aea3, where
the Python backend accepted the URI options. For the power switch, we
still need an additional check to enable the old code path using the
shared radio.

Author: whoenig

cflib/utils/power_switch.py

@@ -39,13 +39,16 @@ def __init__(self, uri):
         self.uri = uri
         uri_augmented = uri+'?safelink=0&autoping=0&ackfilter=0'
         self.link = cflib.crtp.get_link_driver(uri_augmented)
-        # Switch to legacy mode, if uri options are not available
-        if not self.link:
+        # Switch to legacy mode, if uri options are not available or old Python backend is used
+        if not self.link or self.link.get_name() == 'radio':
             uri_parts = cflib.crtp.RadioDriver.parse_uri(uri)
             self.devid = uri_parts[0]
             self.channel = uri_parts[1]
             self.datarate = uri_parts[2]
             self.address = uri_parts[3]
+            if self.link:
+                self.link.close()
+                self.link = None
 
     def platform_power_down(self):
         """ Power down the platform, both NRF and STM MCUs.