add -i workaround suffix for macos

auto-changelog.sh

@@ -17,6 +17,6 @@ while read -r line; do
         BODY=$(echo $line | sed -E 's/(.*):{2}(.*)/\2/') 
     fi
     # add entry to CHANGELOG
-    sed -i "/## Current Develop Branch/a - [#$PR]($URL/pull/$PR): $BODY" CHANGELOG.md;
+    sed -i "" "/## Current Develop Branch/a - [#$PR]($URL/pull/$PR): $BODY" CHANGELOG.md;
 done <<< "$LOG"
 echo "CHANGELOG updated"