Update custom32_LEDPIN_16 build config to use the right relay pin (wled#1385)

The Quin-Dig-Quad has the relay pin on IO19 (Q3).  However, it is on IO12 by default.  Update the build flags for the custom32_LEDPIN_16 build to also move the relay pin to IO19 so it works properly with the board.

Author: larrywal

platformio.ini

@@ -407,7 +407,7 @@ build_flags = ${common.build_flags_esp8266} -D USE_WS2801
 board = esp32dev
 platform = [email protected]
 build_unflags = ${common.build_unflags}
-build_flags = ${common.build_flags_esp32} -D LEDPIN=16 
+build_flags = ${common.build_flags_esp32} -D LEDPIN=16 -D RLYPIN=19
 lib_ignore =
   ESPAsyncTCP
   ESPAsyncUDP