Add some clarifying documentation to the rewrite_contact endpoint option.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@397603 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_pjsip.c

@@ -249,6 +249,11 @@
 				</configOption>
 				<configOption name="rewrite_contact">
 					<synopsis>Allow Contact header to be rewritten with the source IP address-port</synopsis>
+					<description><para>
+						On inbound SIP messages from this endpoint, the Contact header will be changed to have the
+						source IP address and port. This option does not affect outbound messages send to this
+						endpoint.
+					</para></description>
 				</configOption>
 				<configOption name="rtp_ipv6" default="no">
 					<synopsis>Allow use of IPv6 for RTP traffic</synopsis>