sofia-sip: Fix undefined behavior in parsing

Symptoms with LCR: nta outgoing create: invalid URI

Take patch posted to the upstream project and carried by Debian
and Ubuntu for this project. Unroll the different fields by hand
to fix undefined behavior.
diff --git a/recipes-misc/sofia-sip/sofia-sip.inc b/recipes-misc/sofia-sip/sofia-sip.inc
index cd987fa..d282ed1 100644
--- a/recipes-misc/sofia-sip/sofia-sip.inc
+++ b/recipes-misc/sofia-sip/sofia-sip.inc
@@ -5,7 +5,10 @@
 SECTION = "libs"
 DEPENDS = "glib-2.0 openssl"
 
-SRC_URI = "${SOURCEFORGE_MIRROR}/${PN}/${P}.tar.gz"
+SRC_URI = "\
+    ${SOURCEFORGE_MIRROR}/${PN}/${P}.tar.gz \
+    file://msg_parser.c.diff \
+    "
 
 inherit autotools pkgconfig