%python_provide: Don't try to obsolete %_isa provides
    
    Based on recent changes in 04769fa014fe51d623c5b2e110d36bd73d035839,
    packagers might want to use:
    
        %{?python_provide:%python_provide python2-foo%{?_isa}}
    
    ...for backwards compatibility. However the macro adds obsoletes and
    since RPM 4.15, obsoletes with %{?_isa} are not possible:
    
        Only package names are allowed in Obsoletes: Obsoletes: python-foo(x86-64) < ...
    
    To allow such usage, %python_provide now only obsoletes if the argument
    does not end with ")".