Use ghc4pandoc 8.10.7 docker image for linux builds.

9.2.1 still fails without special treatment.

Author: jgm

Makefile

@@ -3,7 +3,7 @@ pandoc=$(shell find dist -name pandoc -type f -exec ls -t {} \; | head -1)
 SOURCEFILES?=$(shell git ls-tree -r master --name-only | grep "\.hs$$")
 BRANCH?=master
 ARCH=$(shell uname -m)
-DOCKERIMAGE=registry.gitlab.b-data.ch/ghc/ghc4pandoc:9.2.1
+DOCKERIMAGE=registry.gitlab.b-data.ch/ghc/ghc4pandoc:8.10.7
 COMMIT=$(shell git rev-parse --short HEAD)
 TIMESTAMP=$(shell date "+%Y%m%d_%H%M")
 LATESTBENCH=$(word 1,$(shell ls -t bench_*.csv 2>/dev/null))