Websocket: make fuzzer cover ws.c (#136)

* websocket: use mandatory option

* websocket: make fuzzer work with corpora example

Author: catenacyber

corpora/curl_fuzzer_ws/test_http_upgrade_to_ws

@@ -571,7 +571,9 @@ int fuzz_set_allowed_protocols(FUZZ_DATA *fuzz)
   allowed_protocols = "tftp";
 #endif
 #ifdef FUZZ_PROTOCOLS_WS
-  allowed_protocols = "ws,wss";
+  // http is required by websockets
+  allowed_protocols = "http,ws,wss";
+  FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_CONNECT_ONLY, 2L));
 #endif
 
   FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_PROTOCOLS_STR, allowed_protocols));