re-enable git-p4 with python3

The git-p4 subpackage has been disabled in Fedora 30 via a4b4f7c (Add
support for disabling python2, 2018-03-28).  Git 2.17.0 was the current
release at that time.  The git-p4 script subsequently gained python3
support which was released in Git 2.27.0 (2020-05-31).

Adjust the python2/python3 conditionals and re-enable git-p4 when either
of them are available.  Put python3 first in the various conditionals,
as that is our primary supported python.  We only include python2 to aid
in building for EL7.

While here, remove the "# endif" comments within the config.mak output.

git.spec

@@ -63,11 +63,11 @@
 %bcond_without              libsecret
 
 # Allow p4 subpackage to be toggled via --with/--without
-# Disable by default if we lack python2 support
-%if %{without python2}
-%bcond_with                 p4
-%else
+# Disable by default if we lack python2 or python3 support
+%if %{with python2} || %{with python3}
 %bcond_without              p4
+%else
+%bcond_with                 p4
 %endif
 
 # Hardening flags for EL-7
@@ -230,12 +230,13 @@ BuildRequires:  perl(POSIX)
 BuildRequires:  perl(Term::ReadLine)
 BuildRequires:  perl(Test::More)
 BuildRequires:  perl(Time::HiRes)
+%if %{with python3}
+BuildRequires:  python3-devel
+%else
 %if %{with python2}
 BuildRequires:  python2-devel
 %endif
 # endif with python2
-%if %{with python3}
-BuildRequires:  python3-devel
 %endif
 # endif with python3
 BuildRequires:  subversion
@@ -428,7 +429,15 @@ repository.
 %package p4
 Summary:        Git tools for working with Perforce depots
 BuildArch:      noarch
+%if %{with python3}
+BuildRequires:  python3-devel
+%else
+%if %{with python2}
 BuildRequires:  python2-devel
+%endif
+# endif with python2
+%endif
+# endif with python3
 Requires:       git = %{version}-%{release}
 %description p4
 %{summary}.
@@ -510,16 +519,18 @@ INSTALL_SYMLINKS = 1
 GITWEB_PROJECTROOT = %{_localstatedir}/lib/git
 GNU_ROFF = 1
 NO_PERL_CPAN_FALLBACKS = 1
+%if %{with python3}
+PYTHON_PATH = %{__python3}
+%else
 %if %{with python2}
 PYTHON_PATH = %{__python2}
 %else
 NO_PYTHON = 1
 %endif
-# endif with python2
+%endif
 %if %{with asciidoctor}
 USE_ASCIIDOCTOR = 1
 %endif
-# endif with asciidoctor
 htmldir = %{?_pkgdocdir}%{!?_pkgdocdir:%{_docdir}/%{name}-%{version}}
 prefix = %{_prefix}
 perllibdir = %{perl_vendorlib}
@@ -985,6 +996,8 @@ rmdir --ignore-fail-on-non-empty "$testdir"
 %changelog
 * Sat May 22 2021 Todd Zullinger <tmz@pobox.com> - 2.32.0-0.1.rc1
 - update to 2.32.0-rc1
+- rearrange python2/python3 conditionals
+- re-enable git-p4 with python3
 
 * Fri May 21 2021 Jitka Plesnikova <jplesnik@redhat.com> - 2.31.1-3.1
 - Perl 5.34 rebuild