feeds/turrispackages: nextcloud: remove php7-mod-hash

Turris packages feed is using master for fixup releases and develop for minor/major releases, but in case of different OpenWrt versions, there might be removed or changed name of some packages.

I found that php7-mod-hash wont be present in OpenWrt 20.xx release as there are using php 7.4.x and it is part of it. On the other hand, there is php7.2.x in OpenWrt 19.07.