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/auto/configure b/src/auto/configure
index 9fd6888..94f0b64 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -5435,7 +5435,7 @@
 if ${vi_cv_version_luajit+:} false; then :
   $as_echo_n "(cached) " >&6
 else
-   vi_cv_version_luajit=`${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/'`
 fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $vi_cv_version_luajit" >&5
 $as_echo "$vi_cv_version_luajit" >&6; }