resolves #4858 pass site instance to watch plugin
resolves #4858 pass site instance to watch plugin

- prevents the watch plugin from creating a new site instance

gencer/jekyll,alex-kovac/jekyll,pmarsceill/jekyll,darwin/jekyll,tillgrallert/jekyll,alex-kovac/jekyll,jaybe-jekyll/jekyll,tomjohnson1492/jekyll,rlugojr/jekyll,Strangehill/jekyll,ryanshaw/jekyll,rasa2011/rasa2011.github.io,Strangehill/jekyll,xcatliu/jekyllcn,jekyll/jekyll,alfredxing/jekyll,chrisfinazzo/jekyll,tillgrallert/jekyll,alex-kovac/jekyll,alfredxing/jekyll,noikiy/jekyll,pmarsceill/jekyll,chrisfinazzo/jekyll,alfredxing/jekyll,rlugojr/jekyll,rlugojr/jekyll,jaybe-jekyll/jekyll,noikiy/jekyll,x-way/jekyll,noikiy/jekyll,tomjohnson1492/jekyll,jeffkole/jekyll,noikiy/jekyll,tillgrallert/jekyll,getandpost/jekyll.github.io,tomjohnson1492/jekyll,tillgrallert/jekyll,ZDroid/jekyll,alex-kovac/jekyll,ZDroid/jekyll,fulldecent/jekyll,jeffkole/jekyll,yhironaka/yhironaka.github.io,pmarsceill/jekyll,fulldecent/jekyll,tomjohnson1492/jekyll,x-way/jekyll,xcatliu/jekyllcn,jekyll/jekyll,tillgrallert/jekyll,jeffkole/jekyll,Strangehill/jekyll,tomjohnson1492/jekyll,gencer/jekyll,darwin/jekyll,ZDroid/jekyll,darwin/jekyll,x-way/jekyll,jekyll/jekyll,xcatliu/jekyllcn,fulldecent/jekyll,getandpost/jekyll.github.io,jaybe-jekyll/jekyll,rasa2011/rasa2011.github.io,xiebinhqy/jklly_china,xiebinhqy/jklly_china,rasa2011/rasa2011.github.io,jeffkole/jekyll,Strangehill/jekyll,jaybe-jekyll/jekyll,Strangehill/jekyll,chrisfinazzo/jekyll,rlugojr/jekyll,gencer/jekyll,gencer/jekyll,getandpost/jekyll.github.io,gencer/jekyll,ryanshaw/jekyll,alex-kovac/jekyll,ryanshaw/jekyll,xiebinhqy/jklly_china,ryanshaw/jekyll,jekyll/jekyll,x-way/jekyll,fulldecent/jekyll,xcatliu/jekyllcn,xiebinhqy/jklly_china,alfredxing/jekyll,darwin/jekyll,chrisfinazzo/jekyll,pmarsceill/jekyll