Exit if /etc/pve doesn't exist

proxmox/backup.pve.content.sh

@@ -97,6 +97,13 @@ main() {                                                        # {{{
 	## Define all vars
 	define_vars
 
+	## Verify if /etc/pve directory is absent {{{
+	### Display an explicit error message
+	### AND exit with error code 1
+	is_directory_absent /etc/pve \
+		&& printf '%b\n' "${RED}/etc/pve directory doesn't seems available. Are you sure you run this script on a Proxmox host?${RESET}" \
+		&& exit 1
+	## }}}
 	## Verify if the local destination directory is absent {{{
 	### AND create it
 	is_directory_absent "${local_bkp_dir}" \