libpjsip: security bump to 2.7.1

Also add hash for license file

See release notes for details:
https://trac.pjsip.org/repos/milestone/release-2.7.1

Signed-off-by: Adam Duskett <Adamduskett@outlook.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 4bdc4e492ba75d34d859ca15f0c21ec8078785fc)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libpjsip/libpjsip.hash

@@ -1,5 +1,6 @@
-# From http://www.pjsip.org/release/2.7/MD5SUM.TXT
-md5	c0d322261e526cafecc176facbb0bab7  pjproject-2.7.tar.bz2
+# From http://www.pjsip.org/release/2.7.1/MD5SUM.TXT
+md5	99a64110fa5c2debff40e0e8d4676380  pjproject-2.7.1.tar.bz2
 
 # Locally computed
-sha256	1c80621a11c39151b3c2511f06abc8ef031fc712bb2f9e9923b5301b04b28f6b	pjproject-2.7.tar.bz2
+sha256	59fabc62a02b2b80857297cfb10e2c68c473f4a0acc6e848cfefe8421f2c3126	pjproject-2.7.1.tar.bz2
+sha256	8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643	COPYING

package/libpjsip/libpjsip.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBPJSIP_VERSION = 2.7
+LIBPJSIP_VERSION = 2.7.1
 LIBPJSIP_SOURCE = pjproject-$(LIBPJSIP_VERSION).tar.bz2
 LIBPJSIP_SITE = http://www.pjsip.org/release/$(LIBPJSIP_VERSION)
 LIBPJSIP_DEPENDENCIES = libsrtp