Fix FTBFS due to the move of /usr/bin/python into a separate package

See https://fedoraproject.org/wiki/Changes/Move_usr_bin_python_into_separate_package

lv2.spec

@@ -2,7 +2,7 @@
 
 Name:           lv2
 Version:        1.14.0
-Release:        6%{?dist}
+Release:        7%{?dist}
 Summary:        Audio Plugin Standard
 
 # lv2specgen template.html is CC-AT-SA
@@ -76,13 +76,13 @@ sed -i '1s|^#!.*|#!%{__python2}|' lv2specgen/lv2specgen.py
 %build
 export CFLAGS="%{optflags}"
 export LDFLAGS="%{__global_ldflags}"
-./waf configure -vv --prefix=%{_prefix} --libdir=%{_libdir} --debug \
+%{__python2} waf configure -vv --prefix=%{_prefix} --libdir=%{_libdir} --debug \
   --docs --docdir=%{_pkgdocdir} --lv2dir=%{_libdir}/lv2
-./waf -vv %{?_smp_mflags}
+%{__python2} waf -vv %{?_smp_mflags}
 
 %install
 rm -rf %buildroot
-DESTDIR=%buildroot ./waf -vv install
+DESTDIR=%buildroot %{__python2} waf -vv install
 mv %{buildroot}%{_pkgdocdir}/%{name}/lv2plug.in/* %{buildroot}%{_pkgdocdir}
 find %{buildroot}%{_pkgdocdir} -type d -empty | xargs rmdir
 for f in COPYING NEWS README.md ; do
@@ -118,6 +118,9 @@ done
 %{_pkgdocdir}/
 
 %changelog
+* Sun Jul 15 2018 Guido Aulisi <guido.aulisi@gmail.com> - 1.14.0-7
+- Fix FTBFS due to the move of /usr/bin/python into a separate package
+
 * Fri Jul 13 2018 Fedora Release Engineering <releng@fedoraproject.org> - 1.14.0-6
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass_Rebuild