BUG/MINOR: vars: smp_fetch_var() doesn't depend on HTTP but on the session

Thus the SMP_USE_HTTP_ANY dependency is incorrect, we have to depend on
SMP_USE_L5_CLI (the session). It's particularly important for session-wide
variables which are kept across HTTP requests. For now there is no impact
but it will make a difference with tcp-request session rules.
diff --git a/src/vars.c b/src/vars.c
index 4a0c4ed..a3dd85c 100644
--- a/src/vars.c
+++ b/src/vars.c
@@ -654,7 +654,7 @@
 
 static struct sample_fetch_kw_list sample_fetch_keywords = {ILH, {
 
-	{ "var", smp_fetch_var, ARG1(1,STR), smp_check_var, SMP_T_STR, SMP_USE_HTTP_ANY },
+	{ "var", smp_fetch_var, ARG1(1,STR), smp_check_var, SMP_T_STR, SMP_USE_L5CLI },
 	{ /* END */ },
 }};