proftpd: add hash file

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

package/proftpd/proftpd.hash

@@ -0,0 +1,2 @@
+# Locally calculated after checking pgp signature
+sha256	c198b53991ce641eae6b3237e856e59f0bfe8330794145b49cae33f85b6f5370	proftpd-1.3.4d.tar.gz