add xargs to properly check for empty activeChildren string

shredder.sh

@@ -46,6 +46,10 @@ while true; do
   for child in ${children}; do
     activeChildren="${activeChildren} $(ps T | grep $child | awk '{print $1}')"
   done
+
+  # if no active children, trim the whitespace so we can check for empty string
+  
+  activeChildren=$(echo ${activeChildren} | xargs echo)
   if [ -z "${activeChildren}" ]; then
     break
   else