build/pkgs/sage_setup_docbuild/spkg-install: Remove useless use of sage-dist-helpers

Author: Matthias Koeppe

build/pkgs/sage_setup_docbuild/spkg-install

@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 cd src
-. sage-dist-helpers
 # We install directly with setuptools, not with pip, because pip does not handle our symlinks correctly.
 # An alternative would be to build an sdist and then to install the sdist using pip.
 sage-python23 -u setup.py --no-user-cfg install --single-version-externally-managed --root=/