functemplate AST: only encode ident names on py2
functemplate AST: only encode ident names on py2

They are passed as `unicode` types, but the AST only accepts py2
strings.

SusannaMaria/beets,beetbox/beets,MyTunesFreeMusic/privacy-policy,diego-plan9/beets,shamangeorge/beets,artemutin/beets,madmouser1/beets,diego-plan9/beets,lengtche/beets,jackwilsdon/beets,shamangeorge/beets,mosesfistos1/beetbox,sampsyo/beets,mosesfistos1/beetbox,Kraymer/beets,sampsyo/beets,diego-plan9/beets,MyTunesFreeMusic/privacy-policy,mosesfistos1/beetbox,jackwilsdon/beets,ibmibmibm/beets,Kraymer/beets,beetbox/beets,pkess/beets,jackwilsdon/beets,beetbox/beets,artemutin/beets,artemutin/beets,SusannaMaria/beets,madmouser1/beets,xsteadfastx/beets,beetbox/beets,ibmibmibm/beets,MyTunesFreeMusic/privacy-policy,ibmibmibm/beets,lengtche/beets,sampsyo/beets,artemutin/beets,pkess/beets,xsteadfastx/beets,mosesfistos1/beetbox,shamangeorge/beets,diego-plan9/beets,SusannaMaria/beets,SusannaMaria/beets,lengtche/beets,xsteadfastx/beets,Kraymer/beets,Kraymer/beets,sampsyo/beets,lengtche/beets,ibmibmibm/beets,pkess/beets,MyTunesFreeMusic/privacy-policy,madmouser1/beets,shamangeorge/beets,pkess/beets,xsteadfastx/beets,jackwilsdon/beets,madmouser1/beets