test_external: fixed one test that would always use default backend
test_external: fixed one test that would always use default backend

garvitr/sympy,mafiya69/sympy,vipulroxx/sympy,shikil/sympy,Vishluck/sympy,drufat/sympy,kaichogami/sympy,madan96/sympy,jbbskinny/sympy,sahilshekhawat/sympy,ga7g08/sympy,abhiii5459/sympy,wanglongqi/sympy,hrashk/sympy,jamesblunt/sympy,skidzo/sympy,oliverlee/sympy,liangjiaxing/sympy,lidavidm/sympy,jbbskinny/sympy,sahilshekhawat/sympy,Designist/sympy,rahuldan/sympy,kmacinnis/sympy,oliverlee/sympy,yukoba/sympy,madan96/sympy,sahilshekhawat/sympy,Arafatk/sympy,Arafatk/sympy,kevalds51/sympy,saurabhjn76/sympy,iamutkarshtiwari/sympy,wyom/sympy,VaibhavAgarwalVA/sympy,aktech/sympy,sahmed95/sympy,bukzor/sympy,beni55/sympy,emon10005/sympy,AkademieOlympia/sympy,Titan-C/sympy,farhaanbukhsh/sympy,kaichogami/sympy,vipulroxx/sympy,atreyv/sympy,Sumith1896/sympy,drufat/sympy,abloomston/sympy,Titan-C/sympy,AunShiLord/sympy,hargup/sympy,kumarkrishna/sympy,mcdaniel67/sympy,amitjamadagni/sympy,ga7g08/sympy,jamesblunt/sympy,sahmed95/sympy,jaimahajan1997/sympy,meghana1995/sympy,kmacinnis/sympy,Curious72/sympy,madan96/sympy,grevutiu-gabriel/sympy,postvakje/sympy,Designist/sympy,chaffra/sympy,cccfran/sympy,shipci/sympy,beni55/sympy,hrashk/sympy,wyom/sympy,saurabhjn76/sympy,VaibhavAgarwalVA/sympy,lidavidm/sympy,Curious72/sympy,kumarkrishna/sympy,atsao72/sympy,Mitchkoens/sympy,souravsingh/sympy,moble/sympy,MechCoder/sympy,srjoglekar246/sympy,iamutkarshtiwari/sympy,yukoba/sympy,Shaswat27/sympy,rahuldan/sympy,garvitr/sympy,Davidjohnwilson/sympy,saurabhjn76/sympy,ahhda/sympy,atsao72/sympy,minrk/sympy,debugger22/sympy,sunny94/temp,jaimahajan1997/sympy,kevalds51/sympy,moble/sympy,farhaanbukhsh/sympy,Sumith1896/sympy,Gadal/sympy,atreyv/sympy,sampadsaha5/sympy,jerli/sympy,Shaswat27/sympy,maniteja123/sympy,emon10005/sympy,grevutiu-gabriel/sympy,yukoba/sympy,Titan-C/sympy,abloomston/sympy,Gadal/sympy,postvakje/sympy,hargup/sympy,shipci/sympy,MechCoder/sympy,skidzo/sympy,grevutiu-gabriel/sympy,atsao72/sympy,asm666/sympy,hrashk/sympy,abloomston/sympy,debugger22/sympy,postvakje/sympy,Arafatk/sympy,Designist/sympy,diofant/diofant,jerli/sympy,shikil/sympy,wanglongqi/sympy,abhiii5459/sympy,wyom/sympy,cswiercz/sympy,ChristinaZografou/sympy,ga7g08/sympy,MridulS/sympy,abhiii5459/sympy,dqnykamp/sympy,ahhda/sympy,sunny94/temp,meghana1995/sympy,ChristinaZografou/sympy,asm666/sympy,amitjamadagni/sympy,cccfran/sympy,chaffra/sympy,bukzor/sympy,emon10005/sympy,bukzor/sympy,rahuldan/sympy,AkademieOlympia/sympy,shikil/sympy,lidavidm/sympy,MechCoder/sympy,Mitchkoens/sympy,meghana1995/sympy,kmacinnis/sympy,maniteja123/sympy,Vishluck/sympy,vipulroxx/sympy,Mitchkoens/sympy,souravsingh/sympy,minrk/sympy,pandeyadarsh/sympy,drufat/sympy,pandeyadarsh/sympy,skidzo/sympy,sampadsaha5/sympy,atreyv/sympy,debugger22/sympy,cccfran/sympy,pandeyadarsh/sympy,ChristinaZografou/sympy,pbrady/sympy,Sumith1896/sympy,toolforger/sympy,chaffra/sympy,aktech/sympy,Davidjohnwilson/sympy,mafiya69/sympy,kaushik94/sympy,yashsharan/sympy,MridulS/sympy,toolforger/sympy,mafiya69/sympy,Davidjohnwilson/sympy,sahmed95/sympy,Shaswat27/sympy,cswiercz/sympy,flacjacket/sympy,VaibhavAgarwalVA/sympy,iamutkarshtiwari/sympy,AkademieOlympia/sympy,souravsingh/sympy,mcdaniel67/sympy,pbrady/sympy,sunny94/temp,liangjiaxing/sympy,cswiercz/sympy,wanglongqi/sympy,beni55/sympy,lindsayad/sympy,hargup/sympy,AunShiLord/sympy,moble/sympy,AunShiLord/sympy,liangjiaxing/sympy,MridulS/sympy,Vishluck/sympy,maniteja123/sympy,shipci/sympy,jaimahajan1997/sympy,mcdaniel67/sympy,sampadsaha5/sympy,farhaanbukhsh/sympy,kaichogami/sympy,dqnykamp/sympy,kaushik94/sympy,skirpichev/omg,pernici/sympy,oliverlee/sympy,kevalds51/sympy,yashsharan/sympy,kaushik94/sympy,lindsayad/sympy,lindsayad/sympy,jerli/sympy,yashsharan/sympy,dqnykamp/sympy,garvitr/sympy,jbbskinny/sympy,Gadal/sympy,kumarkrishna/sympy,toolforger/sympy,aktech/sympy,ahhda/sympy,jamesblunt/sympy,Curious72/sympy,pbrady/sympy,asm666/sympy