uri.cpp: remove redundant Userinfo length check

The isHash variable already checks exactly this:
> bool isHash = d_ptr->m_Userinfo.size() == 40;

Change-Id: I7df6a2e2f605751e543909858e88a93a8c2158f5
Reviewed-by: Stepan Salenikovich <stepan.salenikovich@savoirfairelinux.com>