Although many linux distributions use /etc/os-release,
there are some systems that does not use that for OS identification.
(especially for some traditional non-systemd linux distros or macOS)

When these kinds on distros run /misc/install-deps.sh,
message is printed like below:

$ sudo ./install-deps.sh
grep: /etc/os-release: No such file or directory
"" is not supported distro, so please install packages manually.

So this commit adds an exception for those does not use
/etc/os-release.

Signed-off-by: Kang Minchul <tegongkang@gmail.com>

• Commit 282c8eb
• #1452: misc: Add an exception for distros that doesn't use /etc/os-release
• Branch master

Kang Minchul