Fix links for proposal history: Do not insert 'HEAD'
Fix links for proposal history: Do not insert 'HEAD'

Revert to fix a bug introduced in 8f6bc206ccf5 cause it
affected history links for proposals also which did not work.
"HEAD" in the links is not required anymore for pages due to
the change in e40acf38599e .

alkadis/vcv,liqd/adhocracy,SysTheron/adhocracy,liqd/adhocracy,DanielNeugebauer/adhocracy,SysTheron/adhocracy,phihag/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,phihag/adhocracy,alkadis/vcv,SysTheron/adhocracy,alkadis/vcv,phihag/adhocracy,alkadis/vcv,liqd/adhocracy,liqd/adhocracy,DanielNeugebauer/adhocracy,alkadis/vcv,phihag/adhocracy,phihag/adhocracy,DanielNeugebauer/adhocracy