added arm to archs in readme
added arm to archs in readme

Syncbak-Git/go-udtwrapper,Syncbak-Git/go-udtwrapper,Lupus/go-udtwrapper,Syncbak-Git/go-udtwrapper,Lupus/go-udtwrapper,Lupus/go-udtwrapper,Syncbak-Git/go-udtwrapper,Lupus/go-udtwrapper