slapos/obs: Follow "Do not harcode version of wanted Python"

Replace occurences of 2.7 version to:

 * just python part, in case if part was referred
 * to ${python:version} in case string was generated

component/slapos/obs.cfg

@@ -114,7 +114,7 @@ make-options =
 
 [gobject-introspection]
 pre-configure =
-  ln -s ${python2.7:location}/bin/python2.7 ${python2.7:location}/bin/python2.
+  ln -s ${python:location}/bin/python${python:version} ${python:location}/bin/python2.
   sed -i 's#!/opt/slapos/parts/python2.7/bin/python2.7#!${python2.7:location}/bin/python2.7#' ${python2.7:location}/bin/python-config
   libtoolize -c -f
   aclocal -I${pkgconfig:location}/share/aclocal -I${gettext:location}/share/aclocal -I${libtool:location}/share/aclocal -I${glib:location}/share/aclocal
@@ -124,24 +124,24 @@ configure-options +=
 environment +=
   PATH=${autoconf:location}/bin:${automake:location}/bin:${pkgconfig:location}/bin:${libtool:location}/bin:${intltool:location}/bin:${gettext:location}/bin:${glib:location}/bin:${flex:location}/bin:${bison-go:location}/bin:%(PATH)s
   GIR_DIR=${buildout:parts-directory}/${:_buildout_section_name_}/share/gir-1.0
-  CPPFLAGS=-I${glib:location}/include/glib-2.0 -I${glib:location}/lib/glib-2.0/include -I${python2.7:location}/include/python2.7
-  LDFLAGS=-L${glib:location}/lib -Wl,-rpath=${glib:location}/lib -L${libffi:location}/lib -Wl,-rpath=${libffi:location}/lib -lffi -L${python2.7:location}/lib
+  CPPFLAGS=-I${glib:location}/include/glib-2.0 -I${glib:location}/lib/glib-2.0/include -I${python:location}/include/python${python:version}
+  LDFLAGS=-L${glib:location}/lib -Wl,-rpath=${glib:location}/lib -L${libffi:location}/lib -Wl,-rpath=${libffi:location}/lib -lffi -L${python:location}/lib
   ACLOCAL_PATH=${pkgconfig:location}/share/aclocal:${gettext:location}/share/aclocal:${libtool:location}/share/aclocal:${glib:location}/share/aclocal:${intltool:location}/share/aclocal
   M4=${m4:location}/bin/m4
   PERL5LIB=${perl:location}/lib/5.28.1/
 
 post-install = 
-  sed -i 's#!${python2.7:location}/bin/python2.7#!/opt/slapos/parts/python2.7/bin/python2.7#' ${python2.7:location}/bin/python-config
+  sed -i 's#!${python:location}/bin/python${python:version}#!/opt/slapos/parts/python${python:version}/bin/python${python:version}#' ${python:location}/bin/python-config
   rm -rf ${bison-go:location}
 
 [pygobject3]
 pre-configure +=
-  sed -i 's#!/opt/slapos/parts/python2.7/bin/python2.7#!${python2.7:location}/bin/python2.7#' ${python2.7:location}/bin/python-config
+  sed -i 's#!/opt/slapos/parts/python${python:version}/bin/python${python:version}#!${python:location}/bin/python${python:version}#' ${python:location}/bin/python-config
 environment +=
-  CPPFLAGS=-I${glib:location}/include/glib-2.0 -I${glib:location}/lib/glib-2.0/include -I${gettext:location}/include -I${libffi:location}/include -I${python2.7:location}/include/python2.7
-  LDFLAGS=-L${glib:location}/lib -Wl,-rpath=${glib:location}/lib -L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -L${python2.7:location}/lib
+  CPPFLAGS=-I${glib:location}/include/glib-2.0 -I${glib:location}/lib/glib-2.0/include -I${gettext:location}/include -I${libffi:location}/include -I${python:location}/include/python${python:version}
+  LDFLAGS=-L${glib:location}/lib -Wl,-rpath=${glib:location}/lib -L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -L${python:location}/lib
 post-install =
-  sed -i 's#!${python2.7:location}/bin/python2.7#!/opt/slapos/parts/python2.7/bin/python2.7#' ${python2.7:location}/bin/python-config
+  sed -i 's#!${python:location}/bin/python${python:version}#!/opt/slapos/parts/python${python:version}/bin/python${python:version}#' ${python:location}/bin/python-config
 
 [ncurses]
 configure-options =