px_uploader.py: use consistent indenting

This file had the indentending mixed up between 4 and 8 spaces.
This changes it to the Pythonic way of 4 spaces.

Tools/px_uploader.py

@@ -632,7 +632,7 @@ try:
                     # Windows, don't open POSIX ports
                     if "/" not in port:
                         up = uploader(port, args.baud_bootloader, baud_flightstack)
-                    except Exception:
+            except Exception as e:
                 # open failed, rate-limit our attempts
                 time.sleep(0.05)
 
@@ -652,6 +652,7 @@ try:
                     break
 
                 except Exception:
+
                     if not up.send_reboot():
                         break