remove check for non-macs in scripts/build-offline-dev

works fine on ubuntu 20.04 LTS and debian 10 ( buster )

scripts/build/build-offline-dev.sh

@@ -6,7 +6,6 @@ DIST_ROOT="$ORIGIN_ROOT/dist"
 cp -r $ORIGIN_ROOT/vendor $DIST_ROOT;
 
 # replace online refs using offline-refs (so I can work offline too)
-if [[ $OSTYPE == darwin* ]]; then
   # replace in index.html
   sed -i'' \
       -e "s|//cdn.jsdelivr.net/npm|../vendor|g" \
@@ -15,7 +14,3 @@ if [[ $OSTYPE == darwin* ]]; then
   # replace in spec-runners
   sed -i'' "s/\/\/cdnjs.cloudflare.com\/ajax\/libs/..\/vendor/g" $DIST_ROOT/mocha/spec-runner.html
   sed -i'' "s/\/\/cdnjs.cloudflare.com\/ajax\/libs/..\/vendor/g" $DIST_ROOT/jasmine/spec-runner.html
-else
-  echo "To do: make '$0' work on non-Macs";
-  exit 1;
-fi;