Update watch.go
Update watch.go

fix bug with reload static files
before:
on change static file bee reload web page
on change go files bee only reload web page
after:
on change static file bee reload web page
on change go files bee rebuild app without not reload web page.
beego/bee,beego/bee,ogero/bee,qida/bee,qida/bee,amrfaissal/bee,franzwilhelm/bee,BorisBorshevsky/bee