.zshrc: Fix for Firefox on Wayland

Don't try opening Firefox in XWayland when we already have one run-
ning on Wayland.

.zshrc

@@ -15,6 +15,10 @@ bindkey -e
 bindkey    "^[[3~"          delete-char
 bindkey    "^[3;5~"         delete-char
 
+# make Ctrl-arrow work
+bindkey "^[[1;5C" forward-word
+bindkey "^[[1;5D" backward-word
+
 # autocomplete
 autoload -Uz compinit
 compinit
@@ -30,6 +34,9 @@ if [[ "$OSTYPE" =~ ^linux.*$ ]]; then
 
     if [[ -n $WAYLAND_DISPLAY ]]; then
         export MOZ_ENABLE_WAYLAND=1
+        # 2021-06-22: fix "Firefox is already running" message
+        # See: https://mastransky.wordpress.com/2020/03/16/wayland-x11-how-to-run-firefox-in-mixed-environment/
+        export MOZ_DBUS_REMOTE=1
         export KITTY_ENABLE_WAYLAND=1
         export QT_QPA_PLATFORM=wayland-egl
         export CLUTTER_BACKEND=wayland