package/fping: bump version to 4.0

Please note that according to the release notes
https://github.com/schweikert/fping/releases/tag/v4.0

"fping and fping6 are now unified into one binary."

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/fping/fping.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256	2f753094e4df3cdb1d99be1687c0fb7d2f14c0d526ebf03158c8c5519bc78f54	fping-3.16.tar.gz
+sha256 67eb4152b98ad34f99d2eec4e1098a0bb52caf13c0c89cd147349d08190fe8ce  fping-4.0.tar.gz

package/fping/fping.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-FPING_VERSION = 3.16
+FPING_VERSION = 4.0
 FPING_SITE = http://fping.org/dist
 FPING_LICENSE = BSD-like
 FPING_LICENSE_FILES = COPYING