Remove unused WITH_OWN_SUBPROCESS_PY from RPM spec

We don't have a copy of subprocess.py anymore, so we removed that
option from the Makefile.  Let's not leave that cruft around the RPM
spec file either.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git.spec.in

@@ -92,15 +92,14 @@ Perl interface to Git
 %setup -q
 
 %build
-make %{_smp_mflags} CFLAGS="$RPM_OPT_FLAGS" WITH_OWN_SUBPROCESS_PY=YesPlease \
-     WITH_P4IMPORT=YesPlease prefix=%{_prefix} all %{!?_without_docs: doc}
+make %{_smp_mflags} CFLAGS="$RPM_OPT_FLAGS" WITH_P4IMPORT=YesPlease \
+     prefix=%{_prefix} all %{!?_without_docs: doc}
 
 %install
 rm -rf $RPM_BUILD_ROOT
 make %{_smp_mflags} CFLAGS="$RPM_OPT_FLAGS" DESTDIR=$RPM_BUILD_ROOT \
-     WITH_OWN_SUBPROCESS_PY=YesPlease WITH_P4IMPORT=YesPlease \
-     prefix=%{_prefix} mandir=%{_mandir} INSTALLDIRS=vendor \
-     install %{!?_without_docs: install-doc}
+     WITH_P4IMPORT=YesPlease prefix=%{_prefix} mandir=%{_mandir} \
+     INSTALLDIRS=vendor install %{!?_without_docs: install-doc}
 find $RPM_BUILD_ROOT -type f -name .packlist -exec rm -f {} ';'
 find $RPM_BUILD_ROOT -type f -name '*.bs' -empty -exec rm -f {} ';'
 find $RPM_BUILD_ROOT -type f -name perllocal.pod -exec rm -f {} ';'