doc/howto_release.txt: fix flag order for tar-1.30

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@72680 15284696-431f-4ddb-bdfa-cd5b030d7da7

doc/howto_release.txt

@@ -135,7 +135,7 @@ mv * grass-${VERSION}/
 # do not include the debian control files:
 mv grass-${VERSION}/debian .
 # create the package:
-tar cvfzh grass-${VERSION}.tar.gz grass-${VERSION}/* --exclude=.svn
+tar cvfzh grass-${VERSION}.tar.gz --exclude=.svn grass-${VERSION}/*
 # restore src code location:
 mv ./grass-${VERSION}/* .
 rmdir ./grass-${VERSION}