__key_value removes quotes from values

e.g. this

$ cat | cdist -v config -i - localhost << DONE
__key_value GRUB_CMDLINE_LINUX --file /tmp/grub.conf --value '"nomodeset i915.modeset=0 nouveau.modeset=0 cirrus.modeset=0"' --delimiter '='
DONE

results in:

$ cat  /tmp/grub.conf 
GRUB_CMDLINE_LINUX=nomodeset i915.modeset=0 nouveau.modeset=0 cirrus.modeset=0

where it should be:

$ cat  /tmp/grub.conf 
GRUB_CMDLINE_LINUX="nomodeset i915.modeset=0 nouveau.modeset=0 cirrus.modeset=0"