fix dockerfiles

Author: marcoieni

src/ci/docker/host-x86_64/i686-gnu-nopt-1/Dockerfile

@@ -33,4 +33,4 @@ ENV SCRIPT python3 ../x.py test --stage 0 --config /config/nopt-std-config.toml
   --skip tests \
   --skip src \
   --skip coverage-map \
-  --skip coverage-run \
+  --skip coverage-run

src/ci/docker/host-x86_64/i686-gnu-nopt-2/Dockerfile

@@ -31,4 +31,4 @@ ENV SCRIPT python3 ../x.py --stage 2 test \
   # Skip tests that we run in i686-gnu-nopt-1
   --skip compiler \
   --skip library \
-  --skip tidyselftest \
+  --skip tidyselftest