move unset NIX_STORE_DIR in supplementary-groups.sh

to inside the unshare

tests/supplementary-groups.sh

@@ -5,13 +5,13 @@ requireSandboxSupport
 if ! command -p -v unshare; then skipTest "Need unshare"; fi
 needLocalStore "The test uses --store always so we would just be bypassing the daemon"
 
+unshare --mount --map-root-user bash <<EOF
+  source common.sh
+
   # Avoid store dir being inside sandbox build-dir
   unset NIX_STORE_DIR
   unset NIX_STATE_DIR
 
-unshare --mount --map-root-user bash <<EOF
-  source common.sh
-
   setLocalStore () {
     export NIX_REMOTE=\$TEST_ROOT/\$1
     mkdir -p \$NIX_REMOTE