Fix one more deprecated usage of getargspec.
Fix one more deprecated usage of getargspec.

skidzo/sympy,sampadsaha5/sympy,jaimahajan1997/sympy,sampadsaha5/sympy,souravsingh/sympy,skidzo/sympy,madan96/sympy,aktech/sympy,postvakje/sympy,kaushik94/sympy,chaffra/sympy,skidzo/sympy,drufat/sympy,aktech/sympy,jaimahajan1997/sympy,chaffra/sympy,souravsingh/sympy,yashsharan/sympy,jaimahajan1997/sympy,kaushik94/sympy,madan96/sympy,drufat/sympy,aktech/sympy,souravsingh/sympy,kaushik94/sympy,drufat/sympy,postvakje/sympy,sampadsaha5/sympy,postvakje/sympy,yashsharan/sympy,chaffra/sympy,madan96/sympy,yashsharan/sympy