Wrap arguments for `[ -z` in double quotes

bin/background_jobs

@@ -43,7 +43,7 @@ start_sidekiq()
 load_ok()
 {
   sidekiq_pid=$(cat $sidekiq_pidfile)
-  if [ -z $sidekiq_pid ] ; then
+  if [ -z "$sidekiq_pid" ] ; then
     warn "Could not find a PID in $sidekiq_pidfile"
     exit 0
   fi

bin/web

@@ -9,7 +9,7 @@ unicorn_config="$app_root/config/unicorn.rb"
 get_unicorn_pid()
 {
   local pid=$(cat $unicorn_pidfile)
-  if [ -z $pid ] ; then
+  if [ -z "$pid" ] ; then
     echo "Could not find a PID in $unicorn_pidfile"
     exit 1
   fi