Fix double / issue in ExtractTask
Fix double / issue in ExtractTask

Also fix an issue where extracting pot files for plugins ended up creating
a Localedefault.pot file incorrectly.

Fixes #2284

cakephp/cakephp,mvdriel/cakephp,CakeDC/cakephp,tisu2tisu/cakephp,ndm2/cakephp,akintoey/cakephp,web-player/cakephp,eryw/cakephp,jerems02/cakephp,petteyg/cakephp,yinhe007/cakephp,tenkoma/cakephp,pbaire/cakephp,michaelze/cakephp,garethellis36/cakephp,HavokInspiration/cakephp,et304383/passbolt_api,CVO-Technologies/cakephp,jeffblack360/cakephp,mvdriel/cakephp,mvdriel/cakephp,thinkingmedia/cakephp,CakeDC/cakephp,timhoeppner/cakephp,pbaire/cakephp,CVO-Technologies/cakephp,ndm2/cakephp,dakota/cakephp,jeffblack360/cakephp,Balachan27/cakephp,adopico/cakephp,jjj117/cakephp,dkarvounaris/cakephp,jjj117/cakephp,yinhe007/cakephp,nrother/cakephp,nrother/cakephp,bravo-kernel/cakephp,web-player/cakephp,eboominathan/cakephp,et304383/passbolt_api,et304383/passbolt_api,nrother/cakephp,ADmad/cakephp,michaelze/cakephp,thinkingmedia/cakephp,ADmad/cakephp,dakota/cakephp,cakephp/cakephp,dkarvounaris/cakephp,tenkoma/cakephp,khoimt/cakephp-study,elboletaire/cakephp,CVO-Technologies/cakephp,justinyost/cakephp,kumamidori/cakephp,dakota/cakephp,ADmad/cakephp,cakephp-fr/cakephp,adopico/cakephp,kumamidori/cakephp,tisu2tisu/cakephp,burriko/cakephp,burriko/cakephp,michaelze/cakephp,et304383/passbolt_api,Balachan27/cakephp,berrygoudswaard/cakephp,eboominathan/cakephp,garethellis36/cakephp,ADmad/cakephp,adopico/cakephp,elboletaire/cakephp,timhoeppner/cakephp,tenkoma/cakephp,cakephp-fr/cakephp,petteyg/cakephp,bravo-kernel/cakephp,ionas/cakephp,eryw/cakephp,Phillaf/cakephp,erikfig/cakephp,kumamidori/cakephp,gmponos/cakephp,davidyell/cakephp,eryw/cakephp,jeffblack360/cakephp,web-player/cakephp,cakephp-fr/cakephp,khoimt/cakephp-study,ndm2/cakephp,jerems02/cakephp,mvdriel/cakephp,timhoeppner/cakephp,dkarvounaris/cakephp,justinyost/cakephp,Balachan27/cakephp,thinkingmedia/cakephp,cakephp/cakephp,eboominathan/cakephp,HavokInspiration/cakephp,akintoey/cakephp,tgr0ss/cakephp,ndm2/cakephp,HavokInspiration/cakephp,garethellis36/cakephp,pbaire/cakephp,cakephp/cakephp,Phillaf/cakephp,khoimt/cakephp-study,garethellis36/cakephp,ionas/cakephp,bravo-kernel/cakephp,CakeDC/cakephp,jerems02/cakephp,gmponos/cakephp,erikfig/cakephp,davidyell/cakephp,ionas/cakephp,et304383/passbolt_api,tisu2tisu/cakephp,davidyell/cakephp,tgr0ss/cakephp,elboletaire/cakephp,justinyost/cakephp,akintoey/cakephp,tgr0ss/cakephp,petteyg/cakephp,berrygoudswaard/cakephp,jjj117/cakephp,gmponos/cakephp,yinhe007/cakephp,tenkoma/cakephp,CakeDC/cakephp,Phillaf/cakephp,berrygoudswaard/cakephp,burriko/cakephp,erikfig/cakephp,petteyg/cakephp,dakota/cakephp