lastgenre: Replace top-level genre `ska` with `reggae`…
lastgenre: Replace top-level genre `ska` with `reggae`…

… and move relevant genres from the tree to be children of the `reggae`
top-level genre as well as add `roots reggae` to the list.

See discussion at https://github.com/sampsyo/beets/issues/1661

jcoady9/beets,artemutin/beets,jmwatte/beets,sampsyo/beets,Freso/beets,jcoady9/beets,jmwatte/beets,shamangeorge/beets,beetbox/beets,xsteadfastx/beets,m-urban/beets,beetbox/beets,lengtche/beets,swt30/beets,diego-plan9/beets,mried/beets,pkess/beets,jmwatte/beets,swt30/beets,sampsyo/beets,madmouser1/beets,jackwilsdon/beets,SusannaMaria/beets,kelvinhammond/beets,Freso/beets,mosesfistos1/beetbox,kareemallen/beets,Freso/beets,m-urban/beets,xsteadfastx/beets,jackwilsdon/beets,ibmibmibm/beets,jackwilsdon/beets,kelvinhammond/beets,beetbox/beets,shamangeorge/beets,Freso/beets,LordSputnik/beets,sampsyo/beets,LordSputnik/beets,artemutin/beets,jcoady9/beets,Kraymer/beets,LordSputnik/beets,kelvinhammond/beets,parapente/beets,m-urban/beets,diego-plan9/beets,ibmibmibm/beets,mried/beets,mosesfistos1/beetbox,madmouser1/beets,SusannaMaria/beets,MyTunesFreeMusic/privacy-policy,kareemallen/beets,pkess/beets,mosesfistos1/beetbox,parapente/beets,jmwatte/beets,kelvinhammond/beets,madmouser1/beets,Kraymer/beets,jcoady9/beets,diego-plan9/beets,artemutin/beets,ibmibmibm/beets,artemutin/beets,mried/beets,shamangeorge/beets,swt30/beets,kareemallen/beets,MyTunesFreeMusic/privacy-policy,kareemallen/beets,Kraymer/beets,xsteadfastx/beets,shamangeorge/beets,m-urban/beets,MyTunesFreeMusic/privacy-policy,parapente/beets,sampsyo/beets,MyTunesFreeMusic/privacy-policy,Kraymer/beets,SusannaMaria/beets,diego-plan9/beets,pkess/beets,pkess/beets,jackwilsdon/beets,beetbox/beets,SusannaMaria/beets,LordSputnik/beets,lengtche/beets,mosesfistos1/beetbox,swt30/beets,lengtche/beets,madmouser1/beets,mried/beets,xsteadfastx/beets,lengtche/beets,parapente/beets,ibmibmibm/beets