Update debug level list link (#8172)

Author: MatthewSabre

doc/Troubleshooting/debugging.rst

@@ -74,7 +74,7 @@ Debug Level
 All defines for the different levels starts with ``DEBUG_ESP_``
 
 a full list can be found here in the
-`boards.txt <https://github.com/esp8266/Arduino/blob/master/tools/boards.txt.py#L1045-L1047>`__
+`boards.txt <https://github.com/esp8266/Arduino/blob/04c2322721f6865efe0c518be57e795e8643c183/tools/boards.txt.py#L1308-L1309>`__
 
 Example for own debug messages
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^