Relax regex for looking for easystacks

EESSI-install-software.sh

@@ -267,7 +267,7 @@ if command_exists "nvidia-smi"; then
 fi
 
 # use PR patch file to determine in which easystack files stuff was added
-changed_easystacks=$(cat ${pr_diff} | grep '^+++' | cut -f2 -d' ' | sed 's@^[a-z]/@@g' | grep '^easystacks/.*yml$' | egrep -v 'known-issues|missing') 
+changed_easystacks=$(cat ${pr_diff} | grep '^+++' | cut -f2 -d' ' | sed 's@^[a-z]/@@g' | grep 'easystacks/.*yml$' | egrep -v 'known-issues|missing') 
 if [ -z "${changed_easystacks}" ]; then
     echo "No missing installations, party time!"  # Ensure the bot report success, as there was nothing to be build here
 else