MINOR: cache: add method to cache hash

Current HTTP cache hash contains only the Host header and the url path.
That said, request method should also be added to the mix to support
caching other request methods on the same URL. IE GET and OPTIONS.

src/cache.c

@@ -1041,9 +1041,9 @@ enum act_parse_ret parse_cache_store(const char **args, int *orig_arg, struct pr
 	return ACT_RET_PRS_OK;
 }
 
-/* This produces a sha1 hash of the concatenation of the first
+/* This produces a sha1 hash of the concatenation of the HTTP method,
- * occurrence of the Host header followed by the path component if it
+ * the first occurrence of the Host header followed by the path component
- * begins with a slash ('/'). */
+ * if it begins with a slash ('/'). */
 int sha1_hosturi(struct stream *s)
 {
 	struct http_txn *txn = s->txn;
@@ -1056,6 +1056,16 @@ int sha1_hosturi(struct stream *s)
 
 	trash = get_trash_chunk();
 	ctx.blk = NULL;
+
+	switch (txn->meth) {
+	case HTTP_METH_HEAD:
+	case HTTP_METH_GET:
+		chunk_memcat(trash, "GET", 3);
+		break;
+	default:
+		return 0;
+	}
+
 	if (!http_find_header(htx, ist("Host"), &ctx, 0))
 		return 0;
 	chunk_memcat(trash, ctx.value.ptr, ctx.value.len);