disable compiled functemplates if not using PY2
disable compiled functemplates if not using PY2

The AST code needs rewritten for PY3. This is tracked in
https://github.com/beetbox/beets/issues/2058

mosesfistos1/beetbox,jcoady9/beets,xsteadfastx/beets,ibmibmibm/beets,lengtche/beets,madmouser1/beets,ibmibmibm/beets,jackwilsdon/beets,beetbox/beets,SusannaMaria/beets,jackwilsdon/beets,xsteadfastx/beets,jcoady9/beets,jackwilsdon/beets,diego-plan9/beets,artemutin/beets,beetbox/beets,sampsyo/beets,MyTunesFreeMusic/privacy-policy,diego-plan9/beets,lengtche/beets,Kraymer/beets,pkess/beets,shamangeorge/beets,artemutin/beets,xsteadfastx/beets,sampsyo/beets,beetbox/beets,artemutin/beets,diego-plan9/beets,sampsyo/beets,madmouser1/beets,lengtche/beets,ibmibmibm/beets,artemutin/beets,jcoady9/beets,shamangeorge/beets,ibmibmibm/beets,SusannaMaria/beets,diego-plan9/beets,Kraymer/beets,jackwilsdon/beets,shamangeorge/beets,Kraymer/beets,MyTunesFreeMusic/privacy-policy,shamangeorge/beets,Kraymer/beets,mosesfistos1/beetbox,mosesfistos1/beetbox,madmouser1/beets,MyTunesFreeMusic/privacy-policy,pkess/beets,beetbox/beets,xsteadfastx/beets,pkess/beets,lengtche/beets,SusannaMaria/beets,madmouser1/beets,MyTunesFreeMusic/privacy-policy,SusannaMaria/beets,sampsyo/beets,mosesfistos1/beetbox,jcoady9/beets,pkess/beets