renamed the TIMECOND defines to be CURL_ prefixed

lib/http.c

@@ -781,16 +781,16 @@ CURLcode Curl_http(struct connectdata *conn)
       strcpy(buf, "no strftime() support");
 #endif
       switch(data->set.timecondition) {
-      case TIMECOND_IFMODSINCE:
+      case CURL_TIMECOND_IFMODSINCE:
       default:
         add_bufferf(req_buffer,
                     "If-Modified-Since: %s\r\n", buf);
         break;
-      case TIMECOND_IFUNMODSINCE:
+      case CURL_TIMECOND_IFUNMODSINCE:
         add_bufferf(req_buffer,
                     "If-Unmodified-Since: %s\r\n", buf);
         break;
-      case TIMECOND_LASTMOD:
+      case CURL_TIMECOND_LASTMOD:
         add_bufferf(req_buffer,
                     "Last-Modified: %s\r\n", buf);
         break;