Fix issue with odd number of arguments for Hash

[hedrok]

In case sshd -T | grep key returns some lines without spaces Hash creation in communicator.rb failed with ArgumentError "odd number of arguments for Hash".

As only "pubkeyacceptedalgorithms", "pubkeyacceptedkeytypes", "hostkeyalgorithms" are needed, change to ignore lines that have no space.

This fixes error:

/home/vyos/tasks/VD-2244-thread-starvation/vagrant/plugins/communicators/ssh/communicator.rb:879:in `[]': odd number of arguments for Has
h (ArgumentError)

        opts = Hash[*list.split("\n").map{|line| line.split(" ", 2)}.flatten]
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        from /home/vyos/tasks/VD-2244-thread-starvation/vagrant/plugins/communicators/ssh/communicator.rb:879:in `supported_key_types'
        from /home/vyos/tasks/VD-2244-thread-starvation/vagrant/plugins/communicators/ssh/communicator.rb:215:in `ready?'
        from /home/vyos/tasks/VD-2244-thread-starvation/vagrant/plugins/communicators/ssh/communicator.rb:91:in `block in wait_for_ready'
        from /home/vyos/.local/share/gem/ruby/3.3.0/gems/timeout-0.5.0/lib/timeout.rb:222:in `block in timeout'
        from /home/vyos/.local/share/gem/ruby/3.3.0/gems/timeout-0.5.0/lib/timeout.rb:38:in `handle_timeout'
        from /home/vyos/.local/share/gem/ruby/3.3.0/gems/timeout-0.5.0/lib/timeout.rb:231:in `timeout'
        from /home/vyos/tasks/VD-2244-thread-starvation/vagrant/plugins/communicators/ssh/communicator.rb:66:in `wait_for_ready'
        from /home/vyos/tasks/VD-2244-thread-starvation/vagrant/lib/vagrant/action/builtin/wait_for_communicator.rb:19:in `block in call'

I got it while trying to launch NixOS under Vagrant with https://github.com/nix-community/nixbox.git.

list in line 872 of communicator.rb ends with

"rekeylimit 0 0\npubkeyauthoptions none\n\e]0;\a"

I don't know yet where \e]0;\a came from, but anyway I think ignoring lines without spaces here is good idea.

[hashicorp-cla-app]

All committers have signed the CLA.

[A-Helberg]

As mentioned this also happens if the output contains terminal escape sequences, eq. "\e]0;\a" in my case.
A naive solution is to gsub the input string

# OSC: ESC ] ... (BEL or ESC \)
.gsub(/\e\][^\a\e]*(?:\a|\e\\)/, "")
# CSI: ESC [ ... letter
.gsub(/\e\[[0-?]*[ -\/]*[@-~]/, "")

"\e]0;\a" is a sequence to set the terminal title