DOC: Add missing factor of `i` to `special.modstruve` docstring
DOC: Add missing factor of `i` to `special.modstruve` docstring

Closes gh-10161.

Stefan-Endres/scipy,vigna/scipy,grlee77/scipy,arokem/scipy,Eric89GXL/scipy,aeklant/scipy,vigna/scipy,nmayorov/scipy,person142/scipy,scipy/scipy,rgommers/scipy,Eric89GXL/scipy,lhilt/scipy,grlee77/scipy,WarrenWeckesser/scipy,scipy/scipy,grlee77/scipy,Eric89GXL/scipy,Eric89GXL/scipy,perimosocordiae/scipy,anntzer/scipy,tylerjereddy/scipy,endolith/scipy,pizzathief/scipy,jor-/scipy,jamestwebber/scipy,andyfaff/scipy,andyfaff/scipy,zerothi/scipy,e-q/scipy,perimosocordiae/scipy,matthew-brett/scipy,WarrenWeckesser/scipy,vigna/scipy,person142/scipy,andyfaff/scipy,aeklant/scipy,pizzathief/scipy,jor-/scipy,gertingold/scipy,e-q/scipy,endolith/scipy,gertingold/scipy,zerothi/scipy,ilayn/scipy,endolith/scipy,endolith/scipy,perimosocordiae/scipy,nmayorov/scipy,grlee77/scipy,pizzathief/scipy,vigna/scipy,Stefan-Endres/scipy,Stefan-Endres/scipy,tylerjereddy/scipy,mdhaber/scipy,andyfaff/scipy,anntzer/scipy,aeklant/scipy,ilayn/scipy,scipy/scipy,grlee77/scipy,lhilt/scipy,nmayorov/scipy,ilayn/scipy,rgommers/scipy,tylerjereddy/scipy,scipy/scipy,zerothi/scipy,perimosocordiae/scipy,scipy/scipy,andyfaff/scipy,rgommers/scipy,gertingold/scipy,anntzer/scipy,jamestwebber/scipy,lhilt/scipy,pizzathief/scipy,ilayn/scipy,aarchiba/scipy,Stefan-Endres/scipy,mdhaber/scipy,zerothi/scipy,zerothi/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,person142/scipy,ilayn/scipy,mdhaber/scipy,vigna/scipy,jor-/scipy,gertingold/scipy,mdhaber/scipy,perimosocordiae/scipy,ilayn/scipy,anntzer/scipy,tylerjereddy/scipy,jor-/scipy,endolith/scipy,WarrenWeckesser/scipy,lhilt/scipy,jor-/scipy,nmayorov/scipy,aeklant/scipy,e-q/scipy,jamestwebber/scipy,matthew-brett/scipy,aeklant/scipy,mdhaber/scipy,perimosocordiae/scipy,lhilt/scipy,aarchiba/scipy,e-q/scipy,aarchiba/scipy,tylerjereddy/scipy,mdhaber/scipy,arokem/scipy,anntzer/scipy,WarrenWeckesser/scipy,arokem/scipy,andyfaff/scipy,matthew-brett/scipy,person142/scipy,anntzer/scipy,zerothi/scipy,pizzathief/scipy,matthew-brett/scipy,endolith/scipy,Stefan-Endres/scipy,scipy/scipy,gertingold/scipy,aarchiba/scipy,rgommers/scipy,e-q/scipy,WarrenWeckesser/scipy,arokem/scipy,arokem/scipy,nmayorov/scipy,matthew-brett/scipy,Eric89GXL/scipy,jamestwebber/scipy,person142/scipy,jamestwebber/scipy,aarchiba/scipy,rgommers/scipy,WarrenWeckesser/scipy