res_pjsip_diversion: fix double 181

Arming response to both AST_SIP_SESSION_BEFORE_REDIRECTING and
AST_SIP_SESSION_BEFORE_MEDIA causes 302 to to be handled twice,
resulting in to 181 being generated.

Change-Id: I866e5461564644ffb8a5e12b6f1330b50a7b63ab

res/res_pjsip_diversion.c

@@ -682,7 +682,7 @@ static struct ast_sip_session_supplement diversion_supplement = {
 	.incoming_response = diversion_incoming_response,
 	.outgoing_request = diversion_outgoing_request,
 	.outgoing_response = diversion_outgoing_response,
-	.response_priority = AST_SIP_SESSION_BEFORE_REDIRECTING|AST_SIP_SESSION_BEFORE_MEDIA,
+	.response_priority = AST_SIP_SESSION_BEFORE_MEDIA,
 };
 
 static int load_module(void)