Correctly store enabled channels across reloads

rowbot

@@ -284,7 +284,7 @@ alarm-handler() {
 trap alarm-handler ALRM
 
 config-reload() {
-  local file
+  local file key recording
   info "received HUP signal"
 
   for file in "${prog_args[@]}"; do
@@ -311,7 +311,9 @@ config-reload() {
 
   if [[ -v markov_chains[@] ]]; then
     for key in "${!enabled[@]}"; do
-      recording+=",%s=%s" "$key" "${enabled[$key]}"
+      # This is a scalar string, not an array.
+      # shellcheck disable=SC2179
+      recording+=",$key=${enabled[$key]}"
     done
 
     export RECORDING=${recording#,}