replace sed command in omf.remote to work on mac osx too

plugins/omf/omf.remote.fish

@@ -15,7 +15,7 @@
 #
 function omf.remote --argument-names options -d 'List remote plugins and themes'
   set url "https://api.github.com/orgs/oh-my-fish/repos"
-  set page_count (curl -sI "$url?page=1&per_page=100" | sed -nr 's/^Link:.*page=([0-9]+)&per_page=100>; rel="last".*/\1/p')
+  set page_count (curl -sI "$url?page=1&per_page=100" | grep "^Link" | sed 's/Link:.*page=\([0-9]*\)&per_page=100>; rel="last".*/\1/')
 
   if echo $page_count | grep -vE '^[0-9]+$'
     echo "Could not access Github API" >&2