sh.zio.backup: add retry for restic command

usr/local/bin/sh.zio.backup

@@ -76,12 +76,29 @@ function invoke_restic() {
     elif [[ $command == "generate" || $command == "self-update" ]]; then
         say warning "Unsupported command: $command"
     else
+        attempts=10
+        attempts_delay=600
+
+        while true; do
             "$restic_path" \
                 --cache-dir "$cache_dir" \
                 --password-file "$restic_repo_passwd_file" \
                 --repo "$(cat $restic_repo_file)" \
-            --retry-lock 1h \
                 $command $args
+
+            if [[ $? == 0 ]]; then
+                break
+            else
+                if [[ $attempts == 0 ]]; then
+                    say warning "Command failed. No attempts left"
+                    break
+                else
+                    attempts=$((attempts - 1))
+                    say warning "Command failed. Trying again in $attempts_delay seconds ($attempts attempts remaining)..."
+                    sleep $attempts_delay
+                fi
+            fi
+        done
     fi
 }