tune install_reclass function

Change-Id: Ifd0ee4c3b64f7982fce2d5721e4a944313f21154
diff --git a/bootstrap.sh b/bootstrap.sh
index 08fed25..a0cced5 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -373,7 +373,7 @@
   VERSION=${VERSION:-master}
   # tries to replace all local version system version
   for s in $(python -c "import site; print(' '.join(site.getsitepackages()))"); do
-    $SUDO pip install --upgrade --force-reinstall -I \
+    sudo -H pip install --upgrade --force-reinstall -I \
     -t "$s" git+https://github.com/salt-formulas/reclass.git@${VERSION};
   done
 }