dxspot.py: fix bad f-string

dxspot.py

@@ -62,8 +62,8 @@ def on_message(client, userdata, msg):
         return
 
     logging.info('Possible Es Spot: '
-                 + f'{spot['sc']}->{spot['rc']} '
+                 + f'{spot["sc"]}->{spot["rc"]} '
-                 + f'{int(d)}km {spot['rp']}dB')
+                 + f'{int(d)}km {spot["rp"]}dB')
     tracker.add_match(spot['t'])
 
 def update_image(state, font_path=IMG_FONT, output=IMG_OUT_PATH):