MINOR: http: remove the long deprecated "set-cookie()" sample fetch function

This one was marked as deprecated 9 years ago by commit 28376d62c
("MEDIUM: http: merge ACL and pattern cookie fetches into a single one")
and has disappeared from any documentation, so it never appeared in any
released version. Let's remove it now.
diff --git a/src/http_fetch.c b/src/http_fetch.c
index 6e7ac9e..a28cbaf 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -2153,7 +2153,6 @@
 	{ "scook",              smp_fetch_cookie,             ARG1(0,STR),      NULL,    SMP_T_STR,  SMP_USE_HRSHV },
 	{ "scook_cnt",          smp_fetch_cookie_cnt,         ARG1(0,STR),      NULL,    SMP_T_SINT, SMP_USE_HRSHV },
 	{ "scook_val",          smp_fetch_cookie_val,         ARG1(0,STR),      NULL,    SMP_T_SINT, SMP_USE_HRSHV },
-	{ "set-cookie",         smp_fetch_cookie,             ARG1(0,STR),      NULL,    SMP_T_STR,  SMP_USE_HRSHV }, /* deprecated */
 
 	/* shdr is valid only on the response and is used for ACL compatibility */
 	{ "shdr",               smp_fetch_hdr,                ARG2(0,STR,SINT), val_hdr, SMP_T_STR,  SMP_USE_HRSHV },