REGTESTS: Remove unsupported feature command in http_splicing.vtc

A feature command was added to detect if infinite forward is disabled to be
able to skip the script. Unfortunately, it is no supported to evaluate such
expression. Thus remove it. For now, reg-tests must not be executed with
"-dF" option.
diff --git a/reg-tests/http-messaging/http_splicing.vtc b/reg-tests/http-messaging/http_splicing.vtc
index c76ebf3..2456cdd 100644
--- a/reg-tests/http-messaging/http_splicing.vtc
+++ b/reg-tests/http-messaging/http_splicing.vtc
@@ -4,7 +4,6 @@
 
 feature cmd "$HAPROXY_PROGRAM -cc 'version_atleast(2.6-dev0)'"
 feature cmd "$HAPROXY_PROGRAM -cc 'feature(LINUX_SPLICE)'"
-feature cmd "$HAPROXY_PROGRAM -cc '!(globa.tune & GTUNE_NO_FAST_FWD)'"
 feature ignore_unknown_macro
 
 #REGTEST_TYPE=slow