maketgz: remove old *.dist files before making the tarball

To avoid "old crap" unintentionally getting shipped.

Bug: https://curl.haxx.se/mail/lib-2017-08/0050.html
Reported-by: Christian Weisgerber

maketgz

@@ -50,6 +50,13 @@ if test -z "$patch"; then
     exit
 fi
 
+#
+# As a precaution, remove all *.dist files that may be lying around, to reduce
+# the risk of old leftovers getting shipped. The root 'Makefile.dist' is the
+# exception.
+echo "removing all old *.dist files"
+find . -name "*.dist" -a ! -name Makefile.dist -exec rm {} \;
+
 numeric=`perl -e 'printf("%02x%02x%02x\n", '"$major, $minor, $patch);"`
 
 HEADER=include/curl/curlver.h