notify: make a message translatable This message has been overlooked by check-code, because it starts with non-alphabet character ('\'). Making this message translatable seems reasonable, because messages below in same function are already translatable - '\ndiffs (truncated from %d to %d lines):\n\n' - '\ndiffs (%d lines):\n\n' This is also a part of preparation for making "missing _() in ui message" detection of check-code more exact.