Fix calling asdf from make

Make sets various env variables to communicate with itself in cases of
recursive make files.
Notably the `MAKELEVEL` defines the number of nested `make` calls
currently active.

This can cause errors when calling an unrelated make job from within an
outer makefile.
Since `asdf` builds some software from source (using make) we need to
isolate the asdf issued make calls from the outer.

This is done by unsetting the `MAKELEVEL` variable before calling asdf.

Author: ulope

.dockerignore

@@ -3,5 +3,6 @@ contracts/node_modules
 contracts/deployments
 docker/data
 play/work
+play/Dockerfile
 rolling-shutter/bin
 tools/snapshot/dummyserver/dist

rolling-shutter/Makefile

@@ -99,7 +99,10 @@ install-asdf-plugins:
 	../tools/asdf-install-plugins.sh
 
 install-asdf: install-asdf-plugins
-	asdf install
+	# Various packages installed by asdf internally also use make and don't like if an external make has already
+	# tinkered with then environment.
+	# Therefore we unset MAKELEVEL here.
+	env -u MAKELEVEL asdf install
 
 lint:
 	golangci-lint run --tests