Update build.func

Prepare for Proxmox Virtual Environment 8

misc/build.func

@@ -54,7 +54,7 @@ msg_error() {
 
 # This function checks the version of Proxmox Virtual Environment (PVE) and exits if the version is not supported.
 pve_check() {
-  if [ $(pveversion | grep -c "pve-manager/7\.[0-9]") -eq 0 ]; then
+  if ! pveversion | grep -Eq "pve-manager/(7\.[0-9]|8\.[0-9])"; then
     echo -e "${CROSS} This version of Proxmox Virtual Environment is not supported"
     echo -e "Requires PVE Version 7.0 or higher"
     echo -e "Exiting..."