Allow disabling of 100rel support on PJSIP endpoints.

Due to an inversion error, setting 100rel=no would not actually
change the current value of the setting (which defaulted to "yes").
With this fix, the inversion is corrected.
........

Merged revisions 431420 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@431436 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_pjsip/pjsip_configuration.c

@@ -144,7 +144,7 @@ static int prack_handler(const struct aco_option *opt, struct ast_variable *var,
 	if (ast_true(var->value)) {
 		endpoint->extensions.flags |= PJSIP_INV_SUPPORT_100REL;
 	} else if (ast_false(var->value)) {
-		endpoint->extensions.flags &= PJSIP_INV_SUPPORT_100REL;
+		endpoint->extensions.flags &= ~PJSIP_INV_SUPPORT_100REL;
 	} else if (!strcasecmp(var->value, "required")) {
 		endpoint->extensions.flags |= PJSIP_INV_REQUIRE_100REL;
 	} else {