fix ENABLE_MAP unbound variable in reporting block

set +u was added around the ENGINE_BLOCK for-loops but the reporting
lines after ok "Updated settings.yml" still ran under set -u.
bash < 4.4 throws "unbound variable" for ${#ENABLE_MAP[@]} when the
associative array is empty (no --enable-engines argument was given).

Add set +u before the Disabled/Re-enabled info lines; it already covers
the ${#DISABLE_MAP[@]} reference at the end of the script.

https://claude.ai/code/session_012gDnantBmFTWZGCiKyjazx

configure-searxng-safesearch.sh

@@ -197,6 +197,9 @@ set -u
 } > "$SETTINGS"
 
 ok "Updated settings.yml  (safe_search: $SAFE_INT)"
+# bash < 4.4: ${#assoc[@]} on an empty declared array throws "unbound variable"
+# under set -u — disable nounset for the rest of the reporting section
+set +u
 if [[ ${#DISABLE_MAP[@]} -gt 0 ]]; then
   info "Disabled (${#DISABLE_MAP[@]}): $(printf '%s, ' "${!DISABLE_MAP[@]}" | sed 's/, $//')"
 fi