BUG, DOC: Fix heading remap in scipy-optimize directive.
BUG, DOC: Fix heading remap in scipy-optimize directive.

Fixes a bug that replaces the Returns heading with an
incorrect heading size in the generated docstring. This will
cause warnings (treated as errors) with numpydoc 1.2.

endolith/scipy,mdhaber/scipy,WarrenWeckesser/scipy,anntzer/scipy,Stefan-Endres/scipy,scipy/scipy,Stefan-Endres/scipy,endolith/scipy,vigna/scipy,endolith/scipy,anntzer/scipy,andyfaff/scipy,perimosocordiae/scipy,perimosocordiae/scipy,mdhaber/scipy,WarrenWeckesser/scipy,ilayn/scipy,ilayn/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,endolith/scipy,anntzer/scipy,Stefan-Endres/scipy,ilayn/scipy,rgommers/scipy,mdhaber/scipy,WarrenWeckesser/scipy,mdhaber/scipy,andyfaff/scipy,rgommers/scipy,vigna/scipy,andyfaff/scipy,anntzer/scipy,ilayn/scipy,scipy/scipy,rgommers/scipy,perimosocordiae/scipy,ilayn/scipy,scipy/scipy,scipy/scipy,scipy/scipy,vigna/scipy,rgommers/scipy,anntzer/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,scipy/scipy,andyfaff/scipy,ilayn/scipy,vigna/scipy,andyfaff/scipy,endolith/scipy,vigna/scipy,mdhaber/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,anntzer/scipy,andyfaff/scipy,mdhaber/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,endolith/scipy,rgommers/scipy