Add a space after minus sign if following stringpict also starts with '-'
Add a space after minus sign if following stringpict also starts with '-'

Fixes #4335

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