don't launch boot_animation.py if there is no display.

src/boot.py

@@ -39,5 +39,9 @@ if args is not None and len(args) > 0:
     supervisor.set_next_code_file(next_code_file, sticky_on_reload=False, reload_on_error=True,
                                   working_directory="/".join(next_code_file.split("/")[:-1]))
 
+else:
+    # skip boot animation if no display
+    if supervisor.runtime.display is None:
+        supervisor.set_next_code_file("code.py")
     else:
         supervisor.set_next_code_file("boot_animation.py")