This reverts commit 4900bbee17.
The issue that was supposed to fix is now fixed by lazy-loading rpy2 and
makign sure scipy is loaded before that.
That is not quite as nice, but preloading is now causing its own issues
with openblas 0.3.4:
https://github.com/xianyi/OpenBLAS/issues/1936
Those were removed because they were added to openblas itself. There was
an error with that however and it will take some time until the fix
makes its way through staging. For the time being, reverting this part
of 26d5d030fe will fix the sage build.
This commit should be reverted once
408eacbc89 is in master.
