maintainer-scripts: Fix jit documentation build with update_web_docs_git

scripts/update_web_docs_git -r 9.3.0 -d gcc-9.3.0
failed after the sourceware upgrade, there is no python-sphinx10 package and
python3-sphinx is new enough that the docs build succeeded.

2020-03-12  Jakub Jelinek  <jakub@redhat.com>

	* update_web_docs_git: Drop SPHINXBUILD=/usr/bin/sphinx-1.0-build.

maintainer-scripts/ChangeLog

+2020-03-12  Jakub Jelinek  <jakub@redhat.com>
+
+	* update_web_docs_git: Drop SPHINXBUILD=/usr/bin/sphinx-1.0-build.
+
 2020-02-27  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc_release: Add support for -b local-git-repo argument.

maintainer-scripts/update_web_docs_git

@@ -183,15 +183,16 @@ done
 # defaulting to "sphinx-build".
 #
 # sphinx is packaged in Fedora and EPEL 6 within "python-sphinx",
+# in RHEL 8 within "python3-sphinx",
 # and in openSUSE within "python-Sphinx".
 #
 # For EPEL6, python-sphinx is sphinx 0.6.6, which is missing various
 # directives (e.g. ":c:macro:"), so we need the variant
 # python-sphinx10 package.  The latter installs its executable as
 #   /usr/bin/sphinx-1.0-build
-# so we need to override SPHINXBUILD with this when invoking "make".
+# so we needed to override SPHINXBUILD with this when invoking "make".
 pushd gcc/gcc/jit/docs
-make SPHINXBUILD=/usr/bin/sphinx-1.0-build html || true
+make html || true
 popd
 cp -a gcc/gcc/jit/docs/_build/html jit
 mkdir -p $DOCSDIR/jit