Update Firefox.json

Fix image.

template/apps/Firefox.json

@@ -17,7 +17,7 @@
 	],
 	"image_arm64": "lscr.io/linuxserver/firefox:latest",
 	"image_amd64": "lscr.io/linuxserver/firefox:latest",
-	"logo": "https://raw.githubusercontent.com/pi-hosted/pi-hosted/master/images/dashy.png",
+	"logo": "https://raw.githubusercontent.com/pi-hosted/pi-hosted/master/images/firefox.png",
 	"name": "Firefox",
 	"platform": "linux",
 	"ports": [