rtp_engine: keep payload types in correct range

In r428708 additional codecs were added including
a payload type of 128 which is outside of nominal
range of 0-127.  This change moves changes 128 to
96 to avoid causing a pjsip assertion when making
a call to an endpoint configured with allow=all.

ASTERISK-24367 #close
Review: https://reviewboard.asterisk.org/r/4286/



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@430164 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/rtp_engine.c

@@ -2189,7 +2189,8 @@ int ast_rtp_engine_init()
 	add_static_payload(125, ast_format_slin44, 0);
 	add_static_payload(126, ast_format_slin48, 0);
 	add_static_payload(127, ast_format_slin96, 0);
-	add_static_payload(128, ast_format_slin192, 0);
+	/* payload types above 127 are not valid */
+	add_static_payload(96, ast_format_slin192, 0);
 	/* Opus and VP8 */
 	add_static_payload(100, ast_format_vp8, 0);
 	add_static_payload(107, ast_format_opus, 0);