bash: Allow the default tty which should start sway to be customized per machine

bash/.bashrc

@@ -123,7 +123,10 @@ export GTK_IM_MODULE=fcitx
 export QT_IM_MODULE=fcitx
 export SDL_IM_MODULE=fcitx
 export WLR_XWAYLAND=$HOME/.local/bin/Xwayland-noshm
-$MACHINE_START_SWAY && [[ -z "$DISPLAY" && $(tty) == /dev/tty1 ]] && exec sway
+if [ -z "$MACHINE_SWAY_TTY" ]; then
+  export MACHINE_SWAY_TTY=/dev/tty1
+fi
+$MACHINE_START_SWAY && [[ -z "$DISPLAY" && $(tty) == "$MACHINE_SWAY_TTY" ]] && exec sway
 
 # Miscellaneous utilities
 function clamp_filename() {