centos7: recovery fails during grub-config - GRUB2_INSTALL_DEVICES empty

[gdha]

• ReaR version ("/usr/sbin/rear -V"): master

• OS version ("cat /etc/rear/os.conf" or "lsb_release -a" or "cat /etc/os-release"): CentOS/7

• ReaR configuration files ("cat /etc/rear/site.conf" and/or "cat /etc/rear/local.conf"):

OUTPUT=PXE
OUTPUT_PREFIX_PXE=$HOSTNAME

BACKUP=NETFS

• Hardware (PC or PowerNV BareMetal or ARM) or virtual machine (KVM guest or PoverVM LPAR): x86 VM

• System architecture (x86 compatible or PPC64/PPC64LE or what exact ARM device): x86

• Firmware (BIOS or UEFI or Open Firmware) and bootloader (GRUB or ELILO or Petitboot): GRUB

• Storage (lokal disk or SSD) and/or SAN (FC or iSCSI or FCoE) and/or multipath (DM or NVMe): sda

• Description of the issue (ideally so that others can reproduce it):
  Recovery fails during grub-config - GRUB2_INSTALL_DEVICES empty
  See centos7: recovery fails during grub-config - GRUB2_INSTALL_DEVICES empty gdha/rear-automated-testing#65
  It might be related with Fixed, simplified and enhanced GRUB2 installation #1843

• Work-around, if any: fix as described in centos7: recovery fails during grub-config - GRUB2_INSTALL_DEVICES empty gdha/rear-automated-testing#65

[gdha]

the PR fixed the issue