build: repair http disabled but mqtt enabled build

... as the mqtt code reuses the "method" originally used for HTTP.

Closes #6344

lib/http.h

@@ -23,6 +23,17 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
+typedef enum {
+  HTTPREQ_NONE, /* first in list */
+  HTTPREQ_GET,
+  HTTPREQ_POST,
+  HTTPREQ_POST_FORM, /* we make a difference internally */
+  HTTPREQ_POST_MIME, /* we make a difference internally */
+  HTTPREQ_PUT,
+  HTTPREQ_HEAD,
+  HTTPREQ_LAST /* last in list */
+} Curl_HttpReq;
+
 #ifndef CURL_DISABLE_HTTP
 
 #ifdef USE_NGHTTP2
@@ -35,17 +46,6 @@ extern const struct Curl_handler Curl_handler_http;
 extern const struct Curl_handler Curl_handler_https;
 #endif
 
-typedef enum {
-  HTTPREQ_NONE, /* first in list */
-  HTTPREQ_GET,
-  HTTPREQ_POST,
-  HTTPREQ_POST_FORM, /* we make a difference internally */
-  HTTPREQ_POST_MIME, /* we make a difference internally */
-  HTTPREQ_PUT,
-  HTTPREQ_HEAD,
-  HTTPREQ_LAST /* last in list */
-} Curl_HttpReq;
-
 /* Header specific functions */
 bool Curl_compareheader(const char *headerline,  /* line to check */
                         const char *header,   /* header keyword _with_ colon */

lib/urldata.h

@@ -1402,8 +1402,10 @@ struct UrlState {
   int stream_weight;
   CURLU *uh; /* URL handle for the current parsed URL */
   struct urlpieces up;
-#ifndef CURL_DISABLE_HTTP
+#if !defined(CURL_DISABLE_HTTP) || !defined(CURL_DISABLE_MQTT)
   Curl_HttpReq httpreq; /* what kind of HTTP request (if any) is this */
+#endif
+#ifndef CURL_DISABLE_HTTP
   size_t trailers_bytes_sent;
   struct dynbuf trailers_buf; /* a buffer containing the compiled trailing
                                  headers */
@@ -1706,7 +1708,7 @@ struct UserDefined {
                                     the hostname and port to connect to */
   curl_TimeCond timecondition; /* kind of time/date comparison */
   time_t timevalue;       /* what time to compare with */
-#ifndef CURL_DISABLE_HTTP
+#if !defined(CURL_DISABLE_HTTP) || !defined(CURL_DISABLE_MQTT)
   Curl_HttpReq method;   /* what kind of HTTP request (if any) is this */
 #endif
   long httpversion; /* when non-zero, a specific HTTP version requested to