netdata: survive a failed apt update, leave quietly on Cancel

The add-on runs on the Proxmox host, where the enterprise repository without a
subscription answers 401 and apt update exits 100 (2 of 3 failures in three
days). apt_update_safe retries, points at the enterprise repository and
carries on; the netdata repository was fetched fine.

Cancel in the first menu was reported as a failed run.

CHANGELOG.md

@@ -581,14 +581,7 @@ Exercise vigilance regarding copycat or coat-tailing sites that seek to exploit
 
 ### 💾 Core
 
-  - fix: put the reason for a VM failure into its trace [@MickLesk](https://github.com/MickLesk) ([core#200](https://github.com/community-scripts/core/pull/200))
-- fix: check the bridge before creating a container, and its state after start [@MickLesk](https://github.com/MickLesk) ([core#199](https://github.com/community-scripts/core/pull/199))
-- ref: offer to remove only the container this run created [@MickLesk](https://github.com/MickLesk) ([core#198](https://github.com/community-scripts/core/pull/198))
-- feat: report a cancelled tool dialog as an abort and name the failing command [@MickLesk](https://github.com/MickLesk) ([core#197](https://github.com/community-scripts/core/pull/197))
-- feat: check KVM and the host's threads before building a VM [@MickLesk](https://github.com/MickLesk) ([core#196](https://github.com/community-scripts/core/pull/196))
-- ref: give a host tool one log file for the whole run [@MickLesk](https://github.com/MickLesk) ([core#194](https://github.com/community-scripts/core/pull/194))
-- fix: keep a piped stdin when output moves to the log after a hangup [@MickLesk](https://github.com/MickLesk) ([core#193](https://github.com/community-scripts/core/pull/193))
-- fix: pve-LXC: say when the container went away during its setup [@MickLesk](https://github.com/MickLesk) ([core#192](https://github.com/community-scripts/core/pull/192))
+  - fix: pve-LXC: say when the container went away during its setup [@MickLesk](https://github.com/MickLesk) ([core#192](https://github.com/community-scripts/core/pull/192))
 - fix: treat Esc in a VM wizard dialog as leaving the script [@MickLesk](https://github.com/MickLesk) ([core#190](https://github.com/community-scripts/core/pull/190))
 - ref: count a container stopped during a detached install as an abort [@MickLesk](https://github.com/MickLesk) ([core#187](https://github.com/community-scripts/core/pull/187))
 - feat: find the assets of a renamed GitHub repo without the API [@MickLesk](https://github.com/MickLesk) ([core#188](https://github.com/community-scripts/core/pull/188))

tools/addon/netdata.sh

@@ -80,7 +80,7 @@ install() {
   msg_ok "Set up repository"
 
   msg_info "Installing ${APP}"
-  $STD apt update
+  apt_update_safe
   $STD apt install -y netdata
   msg_ok "Installed ${APP}"
   msg_ok "Completed successfully!\n"
@@ -108,7 +108,7 @@ OPTIONS=(Install "Install ${APP} on Proxmox VE"
   Uninstall "Uninstall ${APP} from Proxmox VE")
 
 CHOICE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --title "${APP}" \
-  --menu "Select an option:" 10 58 2 "${OPTIONS[@]}" 3>&1 1>&2 2>&3)
+  --menu "Select an option:" 10 58 2 "${OPTIONS[@]}" 3>&1 1>&2 2>&3) || exit 0
 
 case $CHOICE in
 "Install") install ;;