omv7更换国内源并导入密钥

先导入密钥，别的国内源（如清华）可直接替换网址

wget --quiet --output-document=- https://mirror.nju.edu.cn/openmediavault/openmediavault-plugin-developers/omvextras2026.asc | gpg --dearmor --yes --output "/usr/share/keyrings/omvextras.gpg"

将国内源写入文件

echo "deb [signed-by=/usr/share/keyrings/omvextras.gpg] https://mirror.nju.edu.cn/openmediavault/openmediavault-plugin-developers sandworm main" | sudo tee /etc/apt/sources.list.d/omvextras.list