patch 9.0.1787: Cannot build with latest luajit

Problem:  Cannot build with latest luajit
Solution: adjust sed regexp and don't expect '-' in version output

closes: #12896

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/configure.ac b/src/configure.ac
index cefd0c3..6813d76 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -638,7 +638,7 @@
       if test "X$vi_cv_path_luajit" != "X"; then
 	dnl -- find LuaJIT version
 	AC_CACHE_CHECK(LuaJIT version, vi_cv_version_luajit,
-	[ vi_cv_version_luajit=`${vi_cv_path_luajit} -v 2>&1 | sed 's/LuaJIT \([[0-9.]]*\)\.[[0-9]]\(-[[a-z0-9]]*\)* .*/\1/'` ])
+       [ vi_cv_version_luajit=`${vi_cv_path_luajit} -v 2>&1 | sed 's/LuaJIT \([[0-9.]]*\)\.[[0-9]]\(-\?[[a-z0-9]]*\)* .*/\1/'` ])
 	AC_CACHE_CHECK(Lua version of LuaJIT, vi_cv_version_lua_luajit,
 	[ vi_cv_version_lua_luajit=`${vi_cv_path_luajit} -e "print(_VERSION)" | sed 's/.* //'` ])
 	vi_cv_path_lua="$vi_cv_path_luajit"