data: Properly access formats in capabilities structure when adding codecs.

Formats within a capabilities structure are addressed starting at 0, not 1.
Assuming 1 causes it to exceed an array.

ASTERISK-24389 #close
Reported by: Kevin Harwell
........

Merged revisions 424752 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@424753 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/data.c

@@ -3146,7 +3146,7 @@ int ast_data_add_codecs(struct ast_data *root, const char *node_name, struct ast
 	}
 
 	count = ast_format_cap_count(cap);
-	for (i = 1; i <= count; ++i) {
+	for (i = 0; i < count; ++i) {
 		struct ast_format *fmt;
 
 		fmt = ast_format_cap_get_format(cap, i);