package/libsrtp: bump to version 2.4.2

This is a patch release for version 2 & 2.4, fixing a regression
introduced in 2.4.1.

https://github.com/cisco/libsrtp/releases/tag/v2.4.2

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 232868ffd3ef76f060711adf5ea1e5001e21ef9d)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libsrtp/libsrtp.hash

@@ -1,3 +1,3 @@
 # Locally calculated
-sha256  3cb580928fcd502426809c68406d04aaa5ef1af7ebb0a3a41a52a13576f2fc07  libsrtp-2.4.1.tar.gz
+sha256  3b1bcb14ebda572b04b9bdf07574a449c84cb924905414e4d94e62837d22b628  libsrtp-2.4.2.tar.gz
 sha256  8e19d42a1eec9561f3f347253ddf2e385c55f392f025bb0fd41b88dbf38db5ae  LICENSE

package/libsrtp/libsrtp.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBSRTP_VERSION = 2.4.1
+LIBSRTP_VERSION = 2.4.2
 LIBSRTP_SITE = $(call github,cisco,libsrtp,v$(LIBSRTP_VERSION))
 LIBSRTP_INSTALL_STAGING = YES
 LIBSRTP_LICENSE = BSD-3-Clause